Light emitting display device

ABSTRACT

The present disclosure relates to a light emitting display device including: a substrate; an anode positioned on the substrate; a black pixel defining layer, wherein an opening overlapping an anode is defined in the black pixel defining layer; an emission layer positioned in the opening of the black pixel defining layer; a spacer positioned on the black pixel defining layer and having a step; and a cathode formed on the emission layer, the black pixel defining layer, and the spacer, wherein the spacer has a first portion and a second portion having a lower height than the first portion and integrally formed with the first portion, and the end portion of the second portion is positioned closer to the opening than the end portion of the first portion.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and the benefit of Korean PatentApplication No. 10-2021-0083448 filed in the Korean IntellectualProperty Office (KIPO) on Jun. 25, 2021, the entire contents of whichare incorporated herein by reference.

BACKGROUND 1. Field

The present disclosure relates to a light emitting display device, andmore particularly, to a light emitting display device that reducesreflectance of external light without using a polarizer.

2. Description of the Related Art

A display device is a device that displays a screen, and includes aliquid crystal display (LCD), an organic light emitting diode (OLED)display, and the like. The display device is used in various electronicdevices such as a mobile phone, a navigation device, a digital camera,an electronic book, a portable game machine, and various terminals.

The display device such as the organic light emitting diode display mayhave a structure in which it may be bent or folded using a flexiblesubstrate.

In addition, in the small electronic devices such as portable phones,optical elements such as cameras and optical sensors are formed in thebezel area around the display area, however as the size of theperipheral area of the display area is gradually reduced while the sizeof the screen to be displayed is increased, a technology is beingdeveloped that allows the camera or the optical sensor to be positionedon the back of the display area.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the describedtechnology, and therefore it may contain information that does not formthe prior art that is already known in this country to a person ofordinary skill in the art.

SUMMARY

Embodiments are for lowering reflectance of external light, increasingscratch strength, or improving interlayer adherence.

A light emitting display device according to an embodiment includes: asubstrate; an anode positioned on the substrate; a black pixel defininglayer, wherein an opening overlapping an anode is defined in the blackpixel defining layer; an emission layer positioned in the opening of theblack pixel defining layer; a spacer positioned on the black pixeldefining layer and having a step; and a cathode formed on the emissionlayer, the black pixel defining layer, and the spacer, wherein thespacer has a first portion and a second portion having a lower heightthan the first portion and integrally formed with the first portion, andone of end portions of the second portion is positioned closer to theopening than one of end portions of the first portion.

The second portion may be positioned away from the opening of the blackpixel defining layer by a predetermined distance.

A planar area ratio of the black pixel defining layer covered by thespacer may be 50% or more and 95% or less.

The spacer may be formed of a photosensitive polyimide (PSPI) or apositive type photosensitive organic material, and the black pixeldefining layer may include a light blocking material and be formed of anorganic material having a negative type of black color.

A height of the first portion may be 1.1 μm or more and 2.0 μm or less,and a height of the second portion may be 0.1 μm or more and 0.5 μm orless.

The light emitting display device may further include: an encapsulationlayer positioned on the cathode; a detecting insulating layer and adetecting electrode positioned on the encapsulation layer; and a lightblocking layer and a color filter positioned on the detecting insulatinglayer and the detecting electrode.

The light emitting display device may further include a functional layerdisposed under the cathode and positioned on the black pixel defininglayer, the emission layer, and the spacer, the functional layer mayincludes a hole injection layer, and the hole injection layer may be incontact with the black pixel defining layer and the spacer.

A light emitting display device according to an embodiment includes amain display area and a component area, wherein the component areaincludes: a unit pixel including a plurality of light emitting diodes(LEDs); a component spacer positioned on the periphery of the pluralityof light emitting diodes (LEDs) included in the unit pixel; and a lighttransmission area positioned on the periphery of the unit pixel, and thecomponent spacer includes a first component spacer positioned outsidethe unit pixel and a second component spacer positioned between theplurality of light emitting diodes (LEDs) included in the unit pixel,and the second component spacer has a lower height than the firstcomponent spacer, and the second component spacer and the firstcomponent spacer are spaced apart from each other.

The unit pixel may further include a black pixel defining layer having aplurality of openings, and a plurality of openings of the black pixeldefining layer may correspond one-to-one to a plurality of lightemitting diodes (LEDs) included in the unit pixel.

Four of the first component spacers may be formed outside the unitpixel, and when four first component spacers are connected, a rhombusstructure may be formed on a plane.

The second component spacer may be positioned in a rectangular areaformed by the plurality of light emitting diodes (LEDs) and be formedcrossing between a plurality of openings of the black pixel defininglayer.

The second component spacer may be spaced apart from a plurality ofopenings of the black pixel defining layer by a predetermined distanceon a plane.

The second component spacer may not be positioned in a part between aplurality of openings adjacent to the black pixel defining layer.

The second component spacer may have a protruded structure from right toleft in addition to an H-shape.

An edge positioned at the outermost side of the unit pixel among aplurality of openings of the black pixel defining layer and an edge ofthe second component spacer adjacent to the edge may have a distance ofabout 5 μm from each other.

A boundary portion spacer may be further formed on the boundary areapositioned between the main display area and the component area, and theboundary portion spacer may include a second boundary portion spacerhaving a constant height and having a tapered structure at one end on aboundary with the light transmission area.

The height of the second boundary portion spacer may be 0.1 μm or moreand 0.5 μm or less.

The spacer and the boundary portion spacer may be formed of aphotosensitive polyimide (PSPI) or a positive type of photosensitiveorganic material, and the black pixel defining layer may include a lightblocking material and be formed of an organic material with a negativetype of black color.

An opening of the black pixel defining layer may be positioned in themain display area, the main spacer may be positioned in the periphery ofthe opening in the main display area, the main spacer may include afirst portion and a second portion having a lower height than the firstportion and integrally formed with the first portion, and the secondportion may be positioned close to the opening in the main display area.

The planar area ratio of the black pixel defining layer covered by themain spacer may be 50% or more and 95% or less.

According to embodiments, a ratio at which the external light isreflected may be reduced by using the black pixel defining layer for apixel definition layer that separates the emission layers from eachother instead of a polarizer. By forming the spacer with the step on theblack pixel defining layer that separates the emission layers from eachother, it is possible to increase the search strength and reduce anoccurrence rate of dark spot defects according to pressing pressure. Onthe other hand, by forming the spacer having the step on the black pixeldefining layer that separates the emission layers from each other,adherence with the functional layer positioned on the black pixeldefining layer and the spacer may be improved, thereby improving darkspot defects according to the pressure or preventing moisture and airfrom being penetrating from the outside.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view showing a usage state of a lightemitting display device according to an embodiment.

FIG. 2 is an exploded perspective view of a light emitting displaydevice according to an embodiment.

FIG. 3 is a block diagram of a light emitting display device accordingto an embodiment.

FIG. 4 is a top plan view showing an enlarged partial area of a lightemitting display panel according to an embodiment.

FIG. 5 is a perspective view schematically illustrating a light emittingdisplay device according to another embodiment.

FIG. 6 is a top plan view showing a first element area of a lightemitting display panel according to another embodiment.

FIG. 7 is a schematic cross-sectional view of a display panel accordingto an embodiment.

FIG. 8 is an enlarged cross-sectional view of some portion of a displaypanel according to an embodiment.

FIG. 9 is a top plan view of some portion of a display panel accordingto an embodiment.

FIG. 10 is an enlarged view of some portion of a display panel accordingto an embodiment.

FIG. 11 is a view showing a flat structure corresponding to a photographtaken of a part of a display panel according to an embodiment.

FIG. 12 is a view showing and distinguishing each position and thicknessin a cross-section taken of a display panel according to an embodiment.

FIG. 13 is a view showing a position of a first portion in a spacer in adisplay panel according to another embodiment.

FIG. 14 and FIG. 15 are views showing a structure of four embodiments.

FIG. 16 is a graph showing comparison of scratch strength for fourembodiments of FIG. 14 and FIG. 15 and a comparative example.

FIG. 17 is a graph showing scratch strength for various embodiments.

FIG. 18 and FIG. 19 are views showing a method of testing adherence anda result thereof.

FIG. 20 is a view showing a chemical formula of a hole injection layerin a functional layer according to an embodiment.

FIG. 21 is a view showing a characteristic change of a positivephotosensitive material included in a comparative example.

FIG. 22 is an enlarged top plan view showing a unit pixel positioned ina first element area and a periphery thereof in a light emitting displaypanel according to an embodiment.

FIG. 23 is an enlarged view of a first element area according to anembodiment.

FIG. 24 is a cross-sectional view of a unit pixel and a lighttransmission area.

FIG. 25 is a top plan view schematically showing a first display areaand a first element area in a light emitting display panel according toan embodiment.

FIG. 26 is an enlarged view taken a first display area and a firstelement area according to an embodiment.

FIG. 27 is a view showing a comparison of scratch strength of a firstelement area according to an embodiment and a comparative example.

FIG. 28 is a circuit diagram of one pixel included in light emittingdisplay panel according to an embodiment.

DETAILED DESCRIPTION

The present disclosure will be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of thedisclosure are shown. As those skilled in the art would realize, thedescribed embodiments may be modified in various different ways, allwithout departing from the spirit or scope of the present disclosure.

In addition, parts not related to the description are omitted for cleardescription of the present disclosure, and like reference numeralsdesignate like elements and similar constituent elements throughout thespecification.

Further, since sizes and thicknesses of constituent members shown in theaccompanying drawings are arbitrarily given for better understanding andease of description, the present disclosure is not limited to theillustrated sizes and thicknesses. In the drawings, the thickness oflayers, films, panels, areas, etc., are exaggerated for clarity. In thedrawings, for better understanding and ease of description, thethicknesses of some layers and areas are exaggerated.

It will be understood that when an element such as a layer, film, area,or substrate is referred to as being “on” another element, it can bedirectly on the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlyon” another element, there are no intervening elements present. Further,in the specification, the word “on” or “above” means positioned on orbelow the object portion, and does not necessarily mean positioned onthe upper side of the object portion based on a gravitational direction.

In addition, unless explicitly described to the contrary, the word“comprise”, and variations such as “comprises” or “comprising”, will beunderstood to imply the inclusion of stated elements but not theexclusion of any other elements.

Further, in the specification, the phrase “on a flat surface” means whenan object portion is viewed from above, and the phrase “on across-section” means when a cross-section taken by vertically cutting anobject portion is viewed from the side.

Hereinafter, a schematic structure of a light emitting display device isdescribed with reference to FIGS. 1, 2, and 3 .

FIG. 1 is a schematic perspective view showing a usage state of a lightemitting display device according to an embodiment, FIG. 2 is anexploded perspective view of a light emitting display device accordingto an embodiment, and FIG. 3 is a block diagram of a light emittingdisplay device according to an embodiment.

A light emitting display device 1000 according to an embodiment as adevice for displaying a motion picture or a still image may be used as adisplay screen of various products such as a television, a laptop, amonitor, an advertisement board, an internet of things (IOT), etc. aswell as portable electronic devices such as a mobile phone, a smartphone, a tablet personal computer, a mobile communication terminal, anelectronic notebook, an e-books, a PMP (portable multimedia player), anavigation device, a UMPC (Ultra Mobile PC), etc. Also, the lightemitting display device 1000 according to an embodiment may be used inwearable devices such as a smart watch, a watch phone, a spectacledisplay, a head mounted display (HMD), etc. Further, a light emittingdisplay device 1000 according to an embodiment may be used as aninstrument panel of a vehicle, a center fascia of a vehicle or a centerinformation display (CID) disposed on a dashboard, a room mirror displayinstead of a side mirror of a vehicle, an entertainment device for aback seat of a vehicle, or a display disposed at a rear surface of afront seat. FIG. 1 , for better comprehension and ease of description,shows that the light emitting display device 1000 is used as a smartphone.

Referring to FIG. 1 , FIG. 2 , and FIG. 3 , the light emitting displaydevice 1000 may display an image toward a third direction DR3 on adisplay surface parallel to a first direction DR1 and a second directionDR2. The display surface on which the image is displayed may correspondto the front surface of the light emitting display device 1000, and maycorrespond to the front surface of a cover window WU. The images mayinclude static images as well as dynamic images.

In the present embodiment, a front (or top) and a back (or bottom) ofeach member are defined based on the direction in which the image isdisplayed. The front and rear surfaces may be opposite to each other inthe third direction DR3, and the normal directions of the front and rearsurfaces may be parallel to the third direction DR3. The separationdistance in the third direction DR3 between the front and rear surfacesmay correspond to the thickness in the third direction DR3 of the lightemitting display panel DP.

The light emitting display device 1000 according to an embodiment maydetect a user's input (refer to a hand in FIG. 1 ) applied from theoutside. The user's input may include various types of external inputssuch as a part of the user's body, light, heat, or pressure. In anembodiment, the user's input is shown with the user's hand applied tothe front. However, the present disclosure is not limited thereto. Theuser's input may be provided in various forms, and the light emittingdisplay device 1000 may sense the user's input applied to the side orrear surface of the light emitting display device 1000 according to thestructure of the light emitting display device 1000.

The light emitting display device 1000 may include a display area DA andnon-display area PA disposed around the display area DA. Meanwhile, thedisplay area DA may be largely divided into a first display area DA1 anda first element area DA2, hereinafter also referred to as a componentarea or a second display area, and in an embodiment, the first displayarea DA1 may include a plurality of pixels for displaying an image, andthe first element area DA2 may include a light transmission area LTA,and additionally may also include a pixel that displays the image. Thefirst element area DA2 may be an area that at least partially overlapswith an optical element ES such as a camera or an optical sensor. FIG. 1shows that the first element area DA2 is provided in a circle shape onthe upper right side of the light emitting display device 1000, but thepresent disclosure is not limited thereto. The first element area DA2may be provided in various numbers and shapes according to the numberand shape of the optical element ES.

The light emitting display device 1000 may receive an external signalrequired for the optical element ES through the first element area DA2or may provide a signal output from the optical element ES to theoutside. In an embodiment, since the first element area DA2 is providedto overlap the light transmission area LTA, the area of the blockingarea BA for forming the light transmission area LTA may be reduced.Here, the blocking area BA is an area having relatively low lighttransmittance compared to the transmission area TA, and may include abezel area.

The light emitting display device 1000 may include a cover window WU, ahousing HM, a light emitting display panel DP, and an optical elementES. In an embodiment, the cover window WU and the housing HM may becombined to constitute an appearance of the light emitting displaydevice 1000.

The cover window WU may include an insulating panel. For example, thecover window WU may be made of glass, plastic, or a combination thereof.

The front surface of the cover window WU may define the front surface ofthe light emitting display device 1000. The transmission area TA may bean optically transparent area. For example, the transmission area TA maybe an area having visible ray transmittance of about 90% or more.

The blocking area BA may define the shape of the transmission area TA.The blocking area BA may be adjacent to the transmission area TA andsurround the transmission area TA. The blocking area BA may be an areahaving relatively low light transmittance compared to the transmissionarea TA. The blocking area BA may include an opaque material that blockslight. The blocking area BA may have a predetermined color. The blockingarea BA may be defined by a transparent substrate defining thetransmission area TA and a bezel layer provided separately, or by an inklayer formed by inserting or coloring the transparent substrate.

The light emitting display panel DP may include a display panel DP fordisplaying an image, a touch sensor TS, and a driving unit 50. The lightemitting display panel DP may include a front surface including adisplay area DA and a non-display area PA. The display area DA may be anarea in which a pixel operates and emits light according to anelectrical signal.

In an embodiment, the display area DA is an area where an image isdisplayed by including a pixel, and may simultaneously be an area wherethe touch sensor TS is positioned on the upper side in the thirddirection DR3 of the pixel so that an external input is sensed.

The transmission area TA of the cover window WU may at least partiallyoverlap the display area DA of the light emitting display panel DP. Forexample, the transmission area TA may overlap the front surface of thedisplay area DA or may overlap at least a portion of the display areaDA. Accordingly, the user may recognize an image through thetransmission area TA or provide an external input based on the image.However, the present disclosure is not limited thereto. For example, inthe display area DA, an area in which an image is displayed and an areain which an external input is detected may be separated from each other.

The non-display area PA of the light emitting display panel DP may atleast partially overlap with the blocking area BA of the cover windowWU. The non-display area PA may be an area covered by the blocking areaBA. The non-display area PA is adjacent to the display area DA and maysurround the display area DA. The image is not displayed in thenon-display area PA, and a driving circuit or driving wiring for drivingthe display area DA may be disposed. The non-display area PA may includea first peripheral area PA1 where the display area DA is positionedoutside and a second peripheral area PA2 including a driving unit 50,and connection wiring and bending area. In the second embodiment of FIG.2 , the first peripheral area PA1 is positioned on three sides of thedisplay area DA, and the second peripheral area PA2 is positioned on oneside of the display area DA. That is, the first peripheral area PA1faces with the first, second, and third sides of the display area DA,and the second peripheral area PA2 faces with the fourth side of thedisplay area DA, which includes the driving unit 50.

In an embodiment, the light emitting display panel DP may be assembledin a flat state with the display area DA and non-display area PA facingthe cover window WU. However, the present disclosure is not limitedthereto. The part of the non-display area PA of the light emittingdisplay panel DP may be bent. In this case, a portion of the non-displayarea PA faces the rear surface of the light emitting display device1000, so that the blocking area BA shown on the front surface of thelight emitting display device 1000 may be reduced, and as shown in FIG.in 2, the second peripheral area PA2 is bent to be positioned on theback side of the display area DA, thereby being assembled.

The display area DA may include a first display area DA1 and a firstelement area DA2. The first element area DA2 may have relatively highlight transmittance compared to the first display area DA1 by includingthe light transmission area LTA. Also, the first element area DA2 mayhave a relatively smaller area than the first display area DA1. Thefirst element area DA2 may be defined as an area overlapping the areawhere the optical element ES is disposed inside the housing HM among thelight emitting display panel DP. In an embodiment, the first elementarea DA2 is shown with a circle shape, but the present disclosure is notlimited thereto, and the first element area DA2 may have various shapessuch as polygons, ellipses, and figures with at least one curved line.

The first display area DA1 may be adjacent to the first element areaDA2. In an embodiment, the first display area DA1 may enclose theentirety of the first element area DA2. However, the present disclosureis not limited thereto. The first display area DA1 may partiallysurround the first element area DA2.

Referring to FIG. 3 , the light emitting display panel DP may includethe display area DA including the display pixel and the touch sensor TS.The light emitting display panel DP may be visually recognized by a userfrom the outside through the transmission area TA by including thepixel, which is a component that generates the image. In addition, thetouch sensor TS may be positioned on the pixel, and may sense anexternal input applied from the outside. The touch sensor TS may detectan external input provided to the cover window WU.

Again, referring to FIG. 2 , the second peripheral area PA2 may includea bending part. The display area DA and the first peripheral area PA1may be in a flat state being substantially parallel to the plane definedby the first direction DR1 and the second direction DR2, and one side ofthe second peripheral area PA2 may be extended from the flat state andthen may have the flat state again after passing through the bendingpart. As a result, at least a part of the second peripheral area PA2 maybe bent and assembled to be positioned on the back side of the displayarea DA. Since at least a portion of the second peripheral area PA2overlaps the display area DA on a plane when being assembled, theblocking area BA of the light emitting display device 1000 may bereduced. However, the present disclosure is not limited thereto. Forexample, the second peripheral area PA2 may not be bent.

The driving unit 50 may be mounted on the second peripheral area PA2,mounted on the bending part, or positioned on one of both sides of thebending part. The driving unit 50 may be provided in a form of a chip.

The driving unit 50 may be electrically connected to the display area DAto transmit an electrical signal to the display area DA. For example,the driving unit 50 may provide data signals to the pixels PX disposedin the display area DA. Alternatively, the driving unit 50 may include atouch driving circuit and may be electrically connected to the touchsensor TS disposed in the display area DA. Meanwhile, the driving unit50 may include various circuits in addition to the above-describedcircuits or may be designed to provide various electrical signals to thedisplay area DA.

Meanwhile, the light emitting display device 1000 may have a pad partpositioned at the end of the second peripheral area PA2, and may beelectrically connected to a flexible printed circuit board (FPCB)including a driving chip by the pad part. Here, the driving chippositioned on the flexible printed circuit board may include variousdriving circuits for driving the light emitting display device 1000 orconnectors for power supply. According to the embodiment, instead of theflexible printed circuit board, a rigid printed circuit board (PCB) maybe used.

The optical element ES may be disposed under the light emitting displaypanel DP. The optical element ES may receive an external inputtransmitted through the first element area DA2 or may output the signalthrough the first element area DA2. In an embodiment, the first elementarea DA2 having relatively high transmittance is provided inside thedisplay area DA, so that the optical element ES may be disposed tooverlap the display area DA, and accordingly, the area or the size ofthe blocking area BA may be reduced.

Referring to FIG. 3 , the light emitting display device 1000 may includealight emitting display panel DP, a power supply module PM, a firstelectric module EM1, and a second electric module EM2. The lightemitting display panel DP, the power supply module PM, the firstelectric module EM1, and the second electric module EM2 may beelectrically connected to each other, and the power supply module PM,the first electric module EM1, and the second electric module EM2 may bedisposed under the display panel DP or stored in the housing HM. In FIG.3 , the display pixel and touch sensor TS positioned in the display areaDA among the configurations of the light emitting display panel DP areillustrated as an example.

The power supply module PM may supply power required for the overalloperation of the light emitting display device 1000. The power supplymodule PM may include a conventional battery module.

The first electric module EM1 and the second electric module EM2 mayinclude various functional modules for operating the light emittingdisplay device 1000. The first electric module EM1 may be directlymounted on a motherboard electrically connected to the display panel DPor mounted on a separate board and electrically connected to themotherboard through a connector (not shown).

The first electric module EM1 may include a control module CM, awireless communication module TM, an image input module IIM, an acousticinput module AIM, a memory MM, and an external interface IF. Some of themodules are not mounted on the motherboard, but may be electricallyconnected to the motherboard through a flexible printed circuit board.

The control module CM may control the overall operation of the lightemitting display device 1000. The control module CM may be amicroprocessor. For example, the control module CM activates ordeactivates the display panel DP. The control module CM may controlother modules such as the image input module IIM or the acoustic inputmodule AIM based on the touch signal received from the display panel DP.

The wireless communication module TM may transmit/receive a wirelesssignal with another terminal using a Bluetooth or Wi-Fi line. Thewireless communication module TM may transmit/receive a voice signalusing a general communication line. The wireless communication module TMincludes a transmitter TM1 that modulates and transmits a signal to betransmitted, and a receiver TM2 that demodulates a received signal.

The image input module IIM may process the image signal to be convertedinto the image data that may be displayed on the light emitting displaypanel DP. The acoustic input module AIM may receive an external acousticsignal input by a microphone in a recording mode, a voice recognitionmode, etc., and convert it into electrical voice data.

The external interface (IF) may serve as an interface connected to anexternal charger, a wired/wireless data port, a card socket (e.g., amemory card, a SIM/UIM card), and the like.

The second electric module EM2 may include an acoustic output moduleAOM, a light emitting module LM, a light receiving module LRM, and acamera module CMM, and at least some of these may be positioned on theback of the display area DA as an optical element ES as shown in FIG. 1and FIG. 2 . The optical element ES may include a light emitting moduleLM, a light receiving module LRM, and a camera module CMM. In addition,the second electric module EM2 may be directly mounted on themotherboard, or mounted on a separate board to be electrically connectedto the light emitting display panel DP through a connector (not shown),or electrically connected to the first electric module EM1.

The acoustic output module AOM may convert the acoustic data receivedfrom the wireless communication module TM or the acoustic data stored inthe memory MM and output it to the outside.

The light emitting module LM may generate and output light. The lightemitting module LM may output infrared rays. For example, the lightemitting module LM may include an LED element. For example, thelight-receiving module LRM may detect infrared rays. The light receivingmodule LRM can be activated when infrared rays above a certain level aredetected. The light receiving module LRM may include a CMOS sensor.After the infrared rays generated by the light emitting module LM areoutput, they are reflected by an external subject (e.g., a user's fingeror face), and the reflected infrared light may be incident on the lightreceiving module LRM. The camera module CMM may take external images.

In an embodiment, the optical element ES may additionally include anoptical detecting sensor or a thermal detecting sensor. The opticalelement ES may detect an external object received through the frontsurface or may provide a sound signal such as voice through the frontsurface to the outside. In addition, the optical element ES may includea plurality of configurations, and is not limited to any one embodiment.

Again, referring to FIG. 2 , the housing HM may be combined with thecover window WU. The cover window WU may be disposed in the frontsurface of the housing HM. The housing HM may be combined with the coverwindow WU to provide a predetermined accommodation space. The lightemitting display panel DP and optical element ES may be accommodated ina predetermined accommodation space provided between the housing HM andthe cover window WU.

The housing HM may include a material with relatively high stiffness.For example, the housing HM may include a plurality of frames and/orplates made of glass, plastic, or metal, or a combination thereof. Thehousing HM may reliably protect the components of the light emittingdisplay device 1000 housed in the interior space from external impact.

In FIG. 1 and FIG. 2 , the optical element ES is shown to be positionedin the display area DA, but according to an embodiment, it may bepositioned in the peripheral area PA disposed outside the display areaDA, and in this case, an area where light is transmitted through theblocking area BA of the cover window WU may be formed.

A structure in which the optical element ES is positioned correspondingto the first element area DA2 positioned in the display area DA isdescribed with reference to FIG. 4 .

FIG. 4 is a top plan view showing an enlarged partial area of a lightemitting display panel according to an embodiment.

In FIG. 4 , a partial area of the light emitting display panel DP havingthe first element area DA2 (hereinafter, also referred to as a componentarea) in which the light transmission area LTA is formed is enlarged andillustrated.

The light emitting display panel DP has the display area DA disposed onthe front surface, and the display area DA is largely divided into afirst display area DA1 (hereinafter referred to as a main display area)and a first element area DA2 (hereinafter also referred to as acomponent area).

In the first display area DA1, a plurality of light emitting diodes(LEDs), and a plurality of pixel circuit units for generating andtransmitting light emitting currents to each of a plurality of lightemitting diodes (LEDs) are formed. Here, one light emitting diode (LED)and one pixel circuit unit are referred to as a pixel PX. In the firstdisplay area DA1, one pixel circuit unit and one light emitting diode(LED) are formed one-to-one. The first display area DA1 is hereinafteralso referred to as a normal display area. In FIG. 4 , the structure ofthe light emitting display panel DP under the cut line is not shown, butthe first display area DA1 may be positioned under the cut line. Thestructure of a spacer 385 having a black pixel defining layer 380 and astep positioned in the first display area DA1 may have a structure ofFIGS. 4, 5, 6, 7, 8, 9, 10, 11, and 12 .

The first element area DA2 is a display area positioned on the frontsurface of the optical element, and has a structure in which a lighttransmission area LTA is additionally formed while a plurality of pixelsare formed.

A boundary area may be positioned between the first display area DA1 andthe first element area DA2.

Although not shown in FIG. 4 , a peripheral area may be furtherpositioned outside the display area DA. In addition, FIG. 4 shows thelight emitting display panel for a mobile phone, however the presentembodiment may be applied if it is the light emitting display panel inwhich the optical element may be positioned on the back surface of thelight emitting display panel, and it may also be a flexible displaypanel. A case of a foldable display panel among the flexible displaypanels is now described with reference to FIG. 5 and FIG. 6 .

FIG. 5 is a perspective view schematically illustrating a light emittingdisplay device according to another embodiment, and FIG. 6 is a top planview showing a first element area of a light emitting display panelaccording to another embodiment.

FIG. 5 and FIG. 6 show the foldable light emitting display panel of thestructure that is folded through a folding line FAX, differently fromFIG. 4 .

In the foldable light emitting display panel DP, the component area DA2may be disposed on the edge of one side as shown in FIG. 5 and FIG. 6 .

The optical element such as a camera or an optical sensor is positionedon the rear surface of the component area DA2 of FIG. 5 and FIG. 6 , andthe light transmission area LTA is positioned in the component area DA2.

Referring to FIG. 5 , man embodiment, the light emitting display device1000 may be the foldable light emitting display device. The lightemitting display device 1000 may be folded outward or inward based onthe folding axis FAX. When being folded outward based on the foldingaxis FAX, the display surface of the light emitting display device 1000is positioned on the outside in the third direction DR3, so that theimages may be displayed in both directions which are the third directionDR3 and the reverse direction of the third direction DR3. When beingfolded inward based on the folding axis FAX, the display surface may notbe visually recognized from the outside.

The light emitting display device 1000 may include a housing, a lightemitting display panel, and a cover window.

In an embodiment, the light emitting display panel may include a displayarea DA and a non-display area PA. The display area DA is an area inwhich an image is displayed, and may be an area in which external inputis simultaneously sensed. The display area DA may be an area in which aplurality of pixels to be described later are disposed.

The display area DA may include a first display area DA1 and a firstelement area DA2. In addition, the first display area DA1 may be dividedinto a first/first display area DA1-1, a first/second element areaDA1-2, and a folding area FA. The first/first display area DA1-1 and thefirst/second element area DA1-2 may be positioned on the left and rightsides, respectively, based on (or at the center) of the folding axisFAX, and the folding area FA may be positioned between the first/firstdisplay area DA1-1 and the first/second element area DA1-2. At thistime, when being folded outward based on the folding axis FAX, thefirst/first display area DA1-1 and the first/second element area DA1-2are positioned on both upper and lower sides in the third direction DR3,and the images may be displayed in both directions. In addition, whenbeing folded inward based on the folding axis FAX, the first/firstdisplay area DA1-1 and the first/second element area DA1-2 may not bevisually recognized from the outside.

On the other hand, in FIG. 6 , the peripheral area PA is also shownoutside the display area DA, and the driving unit 50 is also shown inthe peripheral area PA. In the embodiment of FIG. 6 , the driving unit50 is shown to be positioned in the portion corresponding to the foldingline FAX, but the position of the driving unit 50 may be various.

Hereinafter, an embodiment corresponding to both embodiments in whichthe optical element ES is positioned in the display area DA or outsidedisplay area DA is described with reference to FIGS. 7, 8, 9, 10, 11,12, 13, 14, 15, 16, 17, 18, 19, 20, and 21 .

Now, the structure of the light emitting display panel DP according toan embodiment is described with FIG. 7 .

FIG. 7 is a schematic cross-sectional view of a display panel accordingto an embodiment.

The light emitting display panel DP according to an embodiment maydisplay the image by forming the light emitting diode (LED) on thesubstrate 110, detect the touch by including a plurality of detectingelectrodes 540 and 541, and have a color characteristic of color filters230R, 230G, and 230B due to light emitted from the light emitting diode(LED) by including a light blocking layer 220 and the color filters230R, 230G, and 230B.

In addition, in the light emitting display panel DP of FIG. 7 , theblack pixel defining layer 380 distinguishing the emission layer EMLamong the light emitting diode (LED) is formed of a black color organicmaterial including a light blocking material and a spacer 385(hereinafter referred to as a main spacer) of a structure having a stepis formed on the black pixel defining layer 380. The spacer 385 has ahigh first portion (385-1 hereinafter referred to as a first mainspacer) and a second portion (385-2 hereinafter referred to as a secondmain spacer) having a lower height than the first portion 385-1 andpositioned on the periphery of the first portion 385-1. The firstportion 385-1 and the second portion 385-2 may be integrally formed. Thespacer 385 may reduce a defect rate due to a pressing pressure byincreasing the search strength of the light emitting display panel DP,and also increase adherence with a functional layer FL positioned on thespacer 385 so as to prevent moisture and air from being penetrated fromthe outside. In addition, the high adherence has a merit in that it mayeliminate the problem of decreasing the adherence between layers whenthe light emitting display panel DP has a flexible characteristic and isfolded or unfolded.

In addition, a polarizer is not formed on the front surface of the lightemitting display panel DP according to an embodiment, but as the blackpixel defining layer 380 is used instead, and the light blocking layer220 and the color filter 230 are formed thereon, even if the externallight is incident inside, it may be prevented from being reflected froman anode and transmitted to the user.

The light emitting display panel DP according to an embodiment isdescribed in detail as follows.

The substrate 110 may include a material that does not bend due to arigid characteristic such as glass, or a flexible material that can bebent, such as plastic or polyimide.

A plurality of thin film transistors is formed on the substrate 110, butit is omitted in FIG. 7 , and only an organic layer 180 covering thethin film transistors is shown. One pixel includes the light emittingdiode (LED) and the pixel circuit unit in which a plurality oftransistors and capacitors that transmit a light emitting current to thelight emitting diode (LED) are formed. In FIG. 7 , the pixel circuitunit is not shown, and the structure of the pixel circuit unit may varyaccording to an embodiment. FIG. 7 shows the structure from the organiclayer 180 covering the pixel circuit unit.

On the organic layer 180, the light emitting diode (LED) including ananode (Anode), an emission layer (EML) and a cathode (Cathode).

The anode (Anode) may be composed of a single layer including atransparent conductive oxide film and a metal material, or a multilayerincluding these. The transparent conductive oxide film may include ITO(Indium Tin Oxide), poly-ITO, IZO (Indium Zinc Oxide), IGZO (IndiumGallium Zinc Oxide), and ITZO (Indium Tin Zinc Oxide), and the metalmaterial may include silver (Ag), molybdenum (Mo), copper (Cu), gold(Au), aluminum (Al), etc.

The emission layer EML may be formed of an organic light emittingmaterial, and the adjacent emission layers EML may display differentcolors. On the other hand, according to an embodiment, each emissionlayer EML may display light of the same color due to the color filters230R, 230G, and 230B positioned thereon.

The black pixel defining layer 380 is positioned on the organic layer180 and the anode (Anode), the black pixel defining layer 380 has anopening, the opening overlaps the part of the anode Anode, and theemission layer EML is positioned on the anode (Anode) exposed by theopening. The emission layer EML may be positioned only within theopening of the black pixel defining layer 380, and is separated from theadjacent emission layer EML by the black pixel defining layer 380. Theblack pixel defining layer 380 may be formed of an organic materialhaving a negative type of black color. The organic material having ablack color may include the light blocking material, and the lightblocking material may include a resin or a paste including carbon black,carbon nanotubes, a black dye, metal particles, and for example, nickel,aluminum, molybdenum, alloys thereof, metal oxide particles (e.g.,chromium nitride), and the like. The black pixel defining layer 380 mayhave a black color including a light blocking material, and may have acharacteristic that light is not reflected and is absorbed/blocked.Since the negative type uses the organic material, it may have acharacteristic that s portion covered by the mask is removed.

Here, the black pixel defining layer 380 may be formed in the negativetype, and the spacer 385 may be formed in a positive type, and they mayinclude materials of the same type.

The spacer 385 is formed on the black pixel defining layer 380. Thespacer 385 includes a first portion 385-1 having a high height andpositioned in a narrow area and a second portion 385-2 having a lowheight and positioned in a wide area. FIG. 4 shows that the firstportion 385-1 and the second portion 385-2 are separated through adotted line in the spacer 385. Here, the first portion 385-1 may providea role of securing rigidity against the pressure by strengthening thesearch strength. The second portion 385-2 may serve as a contactassistant between the black pixel defining layer 380 and the overlyingfunctional layer FL. The first portion 385-1 and the second portion385-2 may be formed of the same material, and may be formed of apositive type of photosensitive organic material, and for example, aphotosensitive polyimide (PSPI) may be used. Since it has a positivecharacteristic, the portion not covered by the mask may be removed. Thespacer 385 is transparent so that light may be transmitted and/orreflected.

The large portion of the upper surface of the black pixel defining layer380 is covered by the spacer 385, and the edge of the second portion385-2 has a structure such that it is spaced apart from the edge of theblack pixel defining layer 380, so that the part of the black pixeldefining layer 380 has a structure that is not covered by the spacer385. The second portion 385-2 reinforces the adhesion characteristicbetween the black pixel defining layer 380 and the functional layer FLby covering even the upper surface of the black pixel defining layer 380where the first portion 385-1 is not positioned.

The functional layer FL is positioned on the spacer 385 and the exposedblack pixel defining layer 380, and the functional layer FL may beformed on the entire surface of the light emitting display panel DP. Thefunctional layer FL may include an electron injection layer, an electrontransport layer, a hole transport layer, and a hole injection layer, andthe functional layer FL may be positioned on/under the emission layerEML. That is, the hole injection layer, the hole transport layer, theemission layer EML, the electron transport layer, the electron injectionlayer, and the cathode (Cathode) are sequentially positioned on theanode (Anode), thereby the hole injection layer and the hole transportlayer among the functional layer FL may be positioned under the emissionlayer EML, and the electron transport layer and the electron injectionlayer may be positioned on the emission layer EML.

The cathode (Cathode) may be formed of a light-transmitting electrode ora reflecting electrode. According to an embodiment, the cathode may be atransparent semi-transparent electrode, and may be formed of a metalthin film having a small work function, including lithium (Li), calcium(Ca), lithium fluoride/calcium (LiF/Ca), lithium fluoride/aluminum(LiF/Al), aluminum (Al), silver (Ag), magnesium (Mg), and a compoundthereof. In addition, a transparent conductive oxide (TCO) such asindium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), orindium oxide (In₂O₃) may be further disposed on the metal thin film. Thecathode may be integrally formed over the entire surface of the lightemitting display panel DP.

An encapsulation layer 400 is positioned on the cathode (Cathode). Theencapsulation layer 400 includes at least one inorganic layer and atleast one organic layer, and in FIG. 7 , it has a triple layer structureincluding the first inorganic encapsulation layer 401, the organicencapsulation layer 402, and the second inorganic encapsulation layer403. The encapsulation layer 400 may protect the emission layer EMLformed of an organic material from moisture or oxygen that may be flowedin from the outside. According to an embodiment, the encapsulation layer400 may include a structure in which an inorganic layer and an organiclayer are sequentially further stacked.

A detecting insulating layer (501, 510, and 511) and a plurality ofdetecting electrodes 540 and 541 are positioned on the encapsulationlayer 400 for touch sensing. In an embodiment of FIG. 7 , the touch issensed in a capacitive type using two detecting electrodes 540 and 541,but according to an embodiment, the touch may be sensed in a self-captype using only one detecting electrode. A plurality of detectingelectrodes 540 and 541 may be insulated with an intermediate detectinginsulating layer 510 interposed therebetween, a lower detectingelectrode 541 is positioned on the lower detecting insulating layer 501,and an upper detecting electrode 540 is positioned on the intermediatedetecting insulating layer 510, while the upper detecting electrode 540is covered by the upper detecting insulating layer 511. A plurality ofdetecting electrodes 540 and 541 may be electrically connected throughan opening positioned in the intermediate detecting insulating layer510. Here, the detecting electrodes 540 and 541 may include a metal or ametal alloy such as aluminum (Al), copper (Cu), silver (Ag), gold (Au),molybdenum (Mo), titanium (Ti), or tantalum (Ta), and may be composed ofa single layer or multiple layers.

The light blocking layer 220 and the color filters 230R, 230G, and 230Bare positioned on the upper detecting insulating layer 511.

The light blocking layer 220 may be positioned so as to overlap thedetecting electrodes 540 and 541 in a plan view, and may be positionedso as to not overlap the anode in a plan view. This is to prevent theanode and the emission layer EML capable of displaying the image frombeing obscured by the light blocking layer 220 and the detectingelectrodes 540 and 541.

The color filter 230R, 230G, and 230B are positioned on the detectinginsulating layers 501, 510, and 511 and the light blocking layer 220.The color filters 230R, 230G, and 230B include a red color filter 230Rthat transmits red light, a green color filter 230G that transmits greenlight, and a blue color filter 230B that transmits blue light. Each ofthe color filters 230R, 230G, and 230B may be positioned so as tooverlap the anode of the light emitting diode (LED) in a plan view.Since light emitted from the emission layer EML may be emitted whilebeing changed to a corresponding color while passing through the colorfilter, all of the light emitted from the emission layer EML may havethe same color. However, in the emission layer EML, different colors oflight are displayed, and the displayed color may be enhanced by passingthrough the color filter of the same color.

The light blocking layer 220 may be respectively positioned between thecolor filters 230R, 230G, and 230B. According to an embodiment, thecolor filters 230R, 230G, and 230B may be replaced with a colorconversion layer, or may further include a color conversion layer. Thecolor conversion layer may include quantum dots.

A planarization layer 550 covering the color filters 230R, 230G, and230B is positioned on the color filters 230R, 230G, and 230B. Theplanarization layer 550 is for planarizing the upper surface of thelight emitting display panel, and may be a transparent organic insulatorcontaining at least one material selected from a group consisting ofpolyimide, polyamide, acryl resin, benzocyclobutene, and phenol resin.

According to the embodiment, on top of the planarization layer 550, alow refractive layer and an additional planarization layer may befurther positioned to improve front visibility and light outputefficiency of the display panel. Light may be emitted while beingrefracted to the front by the low refractive layer and the additionalplanarization layer having a high refractive characteristic. In thiscase, the low refractive layer and the additional planarization layermay be positioned directly on the color filter 230 while theplanarization layer 550 is omitted according to an embodiment.

In the present embodiment, the polarizer on the planarization layer 550is not included. That is, the polarizer may serve to prevent displaydeterioration that the user recognizes as the external light is incidentand reflected from the anode and the like. However, in the presentembodiment, the black pixel defining layer 380 covers the side of theanode (Anode) to reduce the degree of reflection from the anode (Anode),and the light blocking layer 220 is also formed to reduce the incidenceof light, thereby the structure for preventing the deterioration of thedisplay quality due to the reflection is already included. Therefore,there is no need to separately from the polarizer on the front of thelight emitting display panel DP.

Hereinafter, the structure of the black pixel defining layer 380 and thespacer 385 according to the present embodiment is described in moredetail with reference to FIGS. 8, 9, 10, and 11 .

FIG. 8 is an enlarged cross-sectional view of some portion of a displaypanel according to an embodiment, FIG. 9 is a top plan view of someportion of a display panel according to an embodiment, FIG. 10 is anenlarged view of some portion of a display panel according to anembodiment, and FIG. 11 is a view showing a flat structure correspondingto a photograph taken of a part of a display panel according to anembodiment.

In FIGS. 8, 9, 10, and 11 , the emission layer EML, the functional layerFL, and the cathode (Cathode) are omitted, however in FIG. 8 , toclearly show the relation with the light blocking layer 220, the lightblocking layer 220 and the color filter are additionally shown.

In FIG. 8 , the opening OP is defined in the black pixel defining layer380 and is positioned on the anode (Anode). In addition, the opening OPoverlaps a portion of the anode (Anode) to expose a part of the uppersurface of the anode (Anode). On the exposed anode (Anode) and in theopening OP of the black pixel defining layer 380, although not shown inFIG. 8 , the emission layer EML is positioned. The black pixel defininglayer 380 has a black color so that light is not reflected from aportion of the anode (Anode) covered by the black pixel defining layer380. Meanwhile, the emission layer EML may include different materialsdepending on the color to be displayed, and accordingly, the size of theopening OP of the black pixel defining layer 380 may be determined.Here, the size of the opening OP of the black pixel defining layer 380is related to the lifetime of the emission layer EML, and when thematerial of the emission layer EML is determined, the opening OP may beformed with a size set in consideration of the lifetime.

A spacer 385 having a step structure is formed on the black pixeldefining layer 380. The spacer 385 includes a first portion 385-1 havinga high height and positioned in a narrow area, and a second portion385-2 having a low height and positioned in a wide area. The secondportion 385-2 has a height as high as h2 from the top surface of theblack pixel defining layer 380, and the first portion 385-1 has a heighthigher than the top surface of the second portion 385-2 by h1, therebyhaving a total height of h1+h2 from the top surface of the black pixeldefining layer 380. In one embodiment, the height h1 of the firstportion 385-1 may be about 1.5 μm, and the height h2 of the secondportion 385-2 may have about 0.4 μm. According to an embodiment, theheights of two spacers 385-1 and 385-2 may vary, and the height h2 ofthe second portion 385-2 may be less than half the total height h1+h2 ofthe first portion 385-1. The protruded height of the first portion385-1, that is, the height difference h1 from the second portion 385-2,may be 1.0 μm or more and 1.4 μm or less, and the height h2 of thesecond portion 385-2 may be 0.1 μm or more and 0.5 μm or less. Accordingto an embodiment, the height difference h1 between the first portion385-1 and the second portion 385-2 may have a value of 0.8 μm or moreand 1.0 μm or less. According to an embodiment, the height (h1+h2) ofthe first portion 385-1 may be 1.1 μm or more and 2.0 μm or less.

On the other hand, the second portion 385-2 forms only a horizontalinterval of g−1 from the edge of the black pixel defining layer 380, sothat the edges thereof are spaced apart from each other. Here, theinterval of g−1 corresponds to the area that is not covered by thespacer 385 among the planar area of the black pixel defining layer 380,and the planar area ratio of the black pixel defining layer 380 coveredby spacer 385 may be about 90%, and according to an embodiment, it maybe 50% or more and 95% or less.

According to the structure of the spacer 385 having the step asdescribed above, the scratch strength is strengthened by the structureprotruded by the first portion 385-1 to secure the rigidity against thepressing pressure.

In addition, the adhesion characteristic between the black pixeldefining layer 380 and the functional layer FL is improved by coveringthe area that is not covered by the first portion 385-1 among the uppersurface of the black pixel defining layer 380 while being positioned aswide as the second portion 385-2, thereby strengthening the interlayercontact force. As a result, the adherence increases so that moisture andair are not penetrated from the outside. High adherence has a merit inthat it may eliminate the problem of reducing the adherence between thelayers when being folded or unfolded in the case that the light emittingdisplay panel DP has a flexible characteristic.

Here, the spacer 385 may be formed of photosensitive polyimide (PSPI),and the black pixel defining layer 380 may be formed of an organicmaterial having a negative type of black color.

On the other hand, FIG. 8 also shows the horizontal spacing g−2 betweenthe spacer 385 and the light blocking layer 220. The edge of the secondportion 385-2 is protruded by g−2 that is more than the edge of thelight blocking layer 220, so that it is formed in a wider area. This isto make the opening on the light blocking layer 220 wider than theopening OP of the black pixel defining layer 380 where the emissionlayer EML is positioned so that the light emitted from the emissionlayer EML may be emitted into the side at a certain angle.

Such spacer 385 may have the same structure as that of FIG. 9 in a planearea.

FIG. 9 shows the pattern of the anode (Anode), the exposed upper surfaceand the opening OP of the black pixel defining layer 380, the firstportion 385-1, and the second portion 385-2. The first portion 385-1 isindicated by a dark circle, and the second portion 385-2 is entirelyformed except at a portion around the opening OP in a plan view. In theportion where the second portion 385-2 is not positioned, the exposedupper surface of the black pixel defining layer 380 and the opening OPof the black pixel defining layer 380 are positioned, and the emissionlayer EML is also positioned in the opening OP of the black pixeldefining layer 380. Since the second portion 385-2 is formed by acertain horizontal distance from the opening OP of the black pixeldefining layer 380, the second portion 385-2 may be formed entirelyexcept at the area where the opening OP and the exposed black pixeldefining layer 380 are positioned.

When viewing such a structure in a perspective view, it is the same asthat of FIG. 10 .

In FIG. 10 , the structure in which the first portion 385-1 is protrudedis shown, the second portion 385-2 is widely positioned on the peripherythereof, and the exposed upper surface of the black pixel defining layer380 and the opening OP of the black pixel defining layer 380 are formedin the recessed portion where the second portion 385-2 is notpositioned.

FIG. 11 shows the relationship between the plan view and thecross-section view more clearly.

In FIG. 11 , the width (OP-w) of the opening OP of the black pixeldefining layer 380 and the width (SPC-w) of the first portion 385-1 areadditionally shown. The width (OP-w) of the opening OP may be changedaccording to the color displayed by the emission layer EML positionedtherein. In addition, in FIG. 11 , with respect to the interval of theblack pixel defining layer 380 and the edge of the second portion 385-2,the interval (g−1′) with the edge of the upper surface of the blackpixel defining layer 380 has a slight difference from the interval (g−1)in FIG. 8 . As a result, in a plane view, the exposed upper surface ofthe black pixel defining layer 380 is more clearly shown.

Hereinafter, the specific height difference in the light emittingdisplay panel DP according to an embodiment is described with referenceto FIG. 12 .

FIG. 12 is a view showing and distinguishing each position and thicknessin a cross-section taken of a display panel according to an embodiment.

FIG. 12 shows the thicknesses in the various positions of the organicencapsulation layer 402 along the encapsulation layer 400.

In FIG. 12 , the thickness of the actual layer is thin, so it may bedifficult to distinguish it, but there is a color classification foreach layer, so the layers may be distinguished and checked based on thechange of the colors.

The thickness of the layer (the first inorganic encapsulation layer 401,the cathode (Cathode), the functional layer FL, etc.) disposed under theorganic encapsulation layer 402 may be uniformly formed so that thethickness of the spacer 385 and the black pixel defining layer 380 thatare indirectly disposed downwardly may be confirmed.

In FIG. 12 , the thickness of the organic encapsulation layer 402 abovethe first portion 385-1 may have about 4.574 μm or 4.437 μm, and thethickness of the organic encapsulation layer 402 above the secondportion 385-2 may be 5.451 μm, thereby the height difference of thefirst portion 385-1 and the second portion 385-2 may have the value of0.877 μm or more to 1.014 μm or less.

In FIG. 12 , above the portion where the spacer 385 and the black pixeldefining layer 380 are not formed, the thickness of the organicencapsulation layer 402 is 7.108 μm and the total thickness of thespacer 385 and the black pixel defining layer 380 has the value of 2.534μm or more to 2.671 μm or less, thereby the thickness of the black pixeldefining layer 380 may have the value of 1.52 μm or more to 1.794 μm orless.

Hereinafter, the position of the first portion 385-1 according to anembodiment is described with reference to FIG. 13 .

FIG. 13 is a view showing a position of a first portion in a spacer in adisplay panel according to another embodiment.

As shown in FIG. 13 , the second portion 385-2 is formed entirely exceptfor the exposed upper portion and the opening OP of the black pixeldefining layer 380, but it is illustrated that the first portion 385-1may be formed intermittently if necessary. According to FIG. 13 , onlyfour first portions 385-1 are shown, and two first portions 385-1 areformed adjacent to each other. The first portion 385-1 may be variouslypositioned.

Hereinafter, the effect according to the present embodiment is describedwith reference to FIGS. 14, 15, 16, 1, 7, 18, 19, 20 and 21 .

First, the characteristic for the scratch strength is described withreference to FIGS. 14, 15, 16, and 17 .

FIGS. 14, 15, and 16 describes the scratch strength for fourembodiments.

FIG. 14 and FIG. 15 are views showing a structure of four embodiments,and FIG. 16 is a graph showing the comparison of scratch strength forfour embodiments of FIG. 14 and FIG. 15 and a comparative example.

In FIG. 14 and FIG. 15 , the structure of four embodiments is firstdescribed.

In FIG. 14 and FIG. 15 , (A), (B), (C), and (D) are cross-section viewsand top plan views corresponding to each other, respectively, where (A)of FIG. 14 and FIG. 15 is indicated by SP1 in FIG. 16 , (B) is indicatedby SP2, (C) is indicated by SP3, and (D) is indicated by SP4.

The horizontal interval shown in FIG. 14 and FIG. 15 is g−1 of FIG. 5and is the horizontal interval between the edges of the second portion385-2 and the black pixel defining layer 380. On the other hand,referring to FIG. 14 , the height of the second portion 385-2 was allformed to be 0.4 μm.

The values measured through FIG. 14 and FIG. 15 are measured by takingone of the various embodiments manufactured according to Table 1 below.

Meanwhile, in Table 1 below, the value of g−2 of FIG. 5 is also includedand described, and the value of g−2 is the horizontal interval betweenthe spacer 385 and the light blocking layer 220.

TABLE 1 unit: μm SP1 SP2 SP3 SP4 Spacer density All the same as 2.826%g-1 actually 1.8 4.3 7.3 8.8 measured value average g-1 design value 1.33.8 6.8 8.3 g-2 actually 3.92 1.42 −1.58 −3.08 measured value averageg-2 designed value 5.97 3.47 0.47 −1.03

In Table 1, a g−1 design value was designed considering a more etchedvalue (0.5 μm) generated when forming the second portion 385-2, and ag−2 design value was designed considering a less etched value (1.55 μm)generated in the light blocking layer 220 in addition to theadditionally etched value (0.5 μm) of the second portion 385-2 like g−1.As a result, a g−1 actually measured value average has a larger valuethan the g−1 design value by about 0.5 μm, and a g−2 actually measuredvalue average has a smaller value than the g−2 design value by about 2.0μm. For reference, the portion indicated by “a spacer density” in Table1 represents an area ratio of the first portion 385-1 of the spacer 385with respect to an entire area, and may have a value of 1% or more and5% or less according to an embodiment.

On the other hand, in FIG. 16 , two comparative examples Ref.1 and Ref.2are also included.

The comparative example 1 Ref.1 is an example, and as shown in a lowerpart of FIG. 16 , the first portion 385-1 is only formed on the blackpixel defining layer 380 and the second portion 385-2 is not included.

The comparative example 2 (Ref.2) is an example, and as shown in a lowerpart of FIG. 16 , a pixel definition layer 380-1 and a first portion385-1 are formed together as a transparent organic insulating material(for example, a photosensitive polyimide (PSPI)) without using the blackpixel defining layer 380.

A graph of results of testing the scratch strength for all six examplesis shown in FIG. 16 .

In FIG. 16 , the number listed next to each bar graph is the average ofthe scratch strength of the corresponding example.

According to FIG. 16 , it may be confirmed that the embodiments of SP1,SP2, SP3, and SP4 have improved average scratch strength compared to thecomparative example 1 (Ref.1). Since Comparative Example 2 (Ref.2) has ahigher value than Comparative Example 1 Ref.1 in the aspect of thescratch strength, it may be confirmed that only the SP1 and SP2embodiments have the improved average scratch strength compared toComparative Example 2 (Ref.2).

Considering FIG. 16 and Table 1, if the horizontal interval g−1 betweenthe edges of the second portion 385-2 and the black pixel defining layer380 is too large, the scratch strength decreases, so it may have thevalue of 1.8 μm or more and 4.3 μm or less. On the other hand, in a caseof wanting to have the improved scratch strength compared to ComparativeExample 1 (Ref.1), it may have the value of about 1.5 μm or more toabout 8.8 μm or less.

In the above, the horizontal interval g−1 between the edges of thesecond portion 385-2 and the black pixel defining layer 380 was mainlyexamined, and hereinafter, it is changed into a concept of an area ratioand examined through Table 2.

TABLE 2 SP1 SP2 SP3 SP4 Spacer area ratio for entire area 80% 70% 57%50% Spacer area ratio for black pixel 93% 83% 67% 58% defining layer

Considering FIG. 16 and Table 2, it may have the area ratio equivalentto SP1 and SP2, and the area ratio of the spacer 385 for the entire areaof the light emitting display panel DP may have the value of 70% or moreand 80% or less, while the area ratio of the spacer 385 for the areaoccupied by the black pixel defining layer 380 may have the value of 83%or more and 93% or less. On the other hand, if it is desired to have theimproved scratch strength than Comparative Example 1 (Ref. 1), the arearatio of the spacer 385 compared to the area occupied by the black pixeldefining layer 380 may have the value of about 50% or more and about 95%or less.

On the other hand, the scratch strength may be affected by the layerpositioned on the spacer 385, and the scratch strength is also changedby the thickness of the organic encapsulation layer 402 among theencapsulation layer 400, which is the most affected.

Hereinafter, the scratch strength according to the thickness of theorganic encapsulation layer 402 and the height of the second portion385-2 are described with reference to FIG. 17 .

FIG. 17 is a graph showing a scratch strength according to variousembodiments.

FIG. 17 shows a scratch strength for total seven embodiments, and eachembodiment 6.20MN-1, 6.20MN-2, 6.20MN-3, 6.90MN-1, 6.90MN-2, 6.90MN-3,and 7.60MN corresponds to seven embodiments described in Table 3 belowcorrespond one by one from the left.

TABLE 3 Organic-encapsulation layer thickness 6.20 6.90 7.60 μm μm μmSecond portion height 0.20 0.30 0.40 0.20 0.30 0.40 0.40 μm μm μm μm μmμm μm Times 8 10 5 8 10 10 8 Average 2.7N 2.7N 2.6N 2.3N 2.4N 2.6N 2.6NStandard 0.41 0.45 0.63 0.18 0.34 0.86 0.69 deviation

For reference, the test was performed in the state that the black pixeldefining layer 380 of the first portion 385-1 had a height of 1.5 μmfrom the upper surface, respectively.

FIG. 17 shows that the average scratch strength of the seven embodimentsis 2.6N, and Comparative Example 1 (Ref.1) of FIG. 16 shows that theaverage scratch strength is about 1.70 so that it may be easily checkedhow much improved it is.

Since the characteristic of the encapsulation layer 400 is to block thepenetration of moisture or air from the outside, it may be appropriatefor the thickness of the organic encapsulation layer 402 to be thick ata certain level, and the organic encapsulation layer 402 may be formedwith a thickness of 6.9 μm, while the second portion 385-2 may be formedat 0.4 μm.

As above-described, it may be confirmed that the present embodimentbasically has improved scratch strength by having higher scratchstrength than Comparative Example 1 (Ref.1) and has improved scratchstrength rather compared to Comparative Example 2 (Ref.2) according toan embodiment.

Hereinafter, the adherence characteristic of the present embodiment isdescribed with reference to FIG. 18 to FIG. 21 .

First, an adherence test method and a result thereof are described withreference to FIG. 18 and FIG. 19 .

FIG. 18 and FIG. 19 are views showing a method of testing adherence anda result thereof.

FIG. 18 shows the method of conducting the adherence test, and twoexperimental examples (A) and (B) are shown to examine the adherence ofthe present embodiment.

First, in FIG. 18(A), the adherence between a photosensitive polyimide(PSPI) and a hole injection layer HIL among a functional layer FL istested. Here, the photosensitive polyimide (PSPI) may form a spacer 385of a pixel definition layer 380-1 of Comparative Example 2 (Ref.2) ofFIG. 16 .

On the other hand, in FIG. 18(B), the adherence between a black colororganic material (BPDL) for a black pixel defining layer 380 instead ofthe photosensitive polyimide (PSPI) and a hole injection layer HIL of afunctional layer FL is tested.

Here, the photosensitive polyimide (PSPI) or the black color organicmaterial (BPDL) for the black pixel defining layer 380 may be stackedand then cured, then plasma-treated, and then the hole injection layerHIL may be stacked. After that, the adherence test is performed by amethod of attaching a tape on the hole injection layer HIL positionedupward and detecting whether two layers fall apart while peeling it off.

Here, as the hole injection layer HIL, as shown in FIG. 20 , a p-dopedhole injection layer HIL was used.

FIG. 19 shows pictures taken before and after the test for peeling offthe tape in a table, and in FIG. 19 , BPDL is a case including the blackcolor organic material for the black pixel defining layer 380, there area total of three experimental examples, and PSPI is a case including aphotosensitive polyimide.

The three experimental examples (BPDL01, BPDL02, and BPDL03) includingthe black color organic material have the following differences.

BPDL01 is a case that only the black color organic material for theblack pixel defining layer 380 is stacked, BPDL02 is a case that the PAC(positive active compound) material shown in FIG. 21 is added at 5 wt %to the black color organic material, and BPDL03 is a case that the PACmaterial at 10 wt % is added to the black color organic material.

In FIG. 19 , the portion indicated by an arrow indicates the portionwhere the adhesion between two layers is separated, and the portionshown in a dot shape is the portion where the adhesion between twolayers is separated.

As shown in FIG. 19 , the black color organic material for the blackpixel defining layer 380 does not have strong adherence with the holeinjection layer HIL, so it may be confirmed that a portion with pooradhesion occurs in all three experimental examples. However, thephotosensitive polyimide has strong adhesion with the hole injectionlayer HIL, so it may be confirmed that the adhesion does not fall evenafter the test.

As shown in FIG. 19 , it may be confirmed that the adherence with thehole injection layer HIL was greatest when using the photosensitivepolyimide, followed by BPDL03 with the second larger adherence, thenBPDL02 with the third larger adherence, and BPDL01 with the lowestadherence.

Therefore, when the pixel definition layer is formed of the black colororganic material without using a polarizer as in the present embodiment,the adhesion characteristic with the hole injection layer HIL formedthereon is not good, so the second portion 385-2 is additionally formedto reinforce the adhesion characteristic in forming the spacer 385. As aresult, the area in which the black pixel defining layer 380 and thehole injection layer HIL are directly in contact with each other isreduced by covering the upper surface of the black pixel defining layer380, and then the second portion 385-2 formed of the photosensitivepolyimide and the hole injection layer HIL are in contact, thereby theadherence may be strengthened.

The difference in the adherence as described above is theoreticallydescribed with reference to FIG. 20 and FIG. 21 .

FIG. 20 is a view showing a chemical formula of a hole injection layerin a functional layer according to an embodiment, and FIG. 21 is a viewshowing a characteristic change of a positive photosensitive materialincluded in a comparative example.

According to FIG. 20 , the hole injection layer has a P-HIL structuredoped with about 3% of p in addition to a basic HIL material. The P-HILstructure has hydrophilicity.

On the other hand, FIG. 21 shows that a characteristic change as thepositive photosensitive material included in the photosensitivepolyimide is exposed.

That is, as nitrogen N2 and CO are removed, it finally has a hydrophiliccharacteristic.

Therefore, both the hole injection layer and the photosensitivepolyimide have hydrophilicity, so their adherence is high.

In contrast, the black color organic material for the black pixeldefining layer 380 may include carboxylic acid, and has a hydrophobiccharacteristic, so that the adhesion characteristic with the holeinjection layer is not high.

Accordingly, to improve the adhesion characteristic with the holeinjection layer HIL even while using the black pixel defining layer 380,the spacer 385 should have the second portion 385-2 with a low height(0.1 μm-0.5 μm) over a wide area, and the spacer 385 may be formed tocover the black pixel defining layer 380 with an area ratio of 50% ormore and 95% or less, and according to an embodiment, it may be formedwith an area ratio of 90%.

In the above, the structure of the spacer 385 with the black pixeldefining layer 380 and the step in a normal pixel was described.Hereinafter, a structure of a spacer 385 in a pixel of a portion havinga light transmission area LTA and including an optical element such as acamera or a light sensor thereunder while including a light transmissionarea LTA is described with reference to FIGS. 22, 23, 24, 25, 26, and 27.

A plurality of pixels and a plurality of spacers may be formed in aone-unit structure in the first element area DA2, and hereinafter, thestructure of the unit pixel PXU2 positioned in the first element areaDA2 is described.

FIG. 22 is an enlarged top plan view showing a unit pixel positioned ina first element area and a periphery thereof in a light emitting displaypanel according to an embodiment, FIG. 23 is an enlarged view of a firstelement area according to an embodiment, and FIG. 24 is across-sectional view of a unit pixel and a light transmission area.

A planar structure of the unit pixel PXU2 positioned in the firstelement area DA2 is described with reference to FIG. 22 and FIG. 23 .

A one-unit pixel PXU2 includes two red pixels, two blue pixels, and fourgreen pixels, and also includes a plurality of light emitting diodes(LED). FIG. 22 does not show the pixel circuit unit of each pixel, andthe light emitting diode (LED) of each color is shown by R, G, and B.

Two red light emitting diodes (LED) R, two blue light emitting diodes(LED) B, and four green light emitting diodes (LED) G are arranged in arectangular area. Four green light emitting diodes (LED) G are arrangedin the middle row, and the red light emitting diodes (LED) R and theblue light emitting diodes (LED) B are arranged alternately to the leftand right. The light emitting diode (LED) positioned first in the leftcolumn and the light emitting diode (LED) positioned first in the rightcolumn may have different colors.

The spacer positioned in the first element area DA2 (hereinafter alsoreferred to as a component spacer) includes a first component spacer385-1 t which is formed high and a second component spacer 385-2 t whichis formed low. The first component spacer 385-1 t and the secondcomponent spacer 385-2 t are separated from each other.

The first component spacer 385-1 t may have the height corresponding tothe first portion 385-1 of the main spacer 385 and may include the samematerial, and the second component spacer 385-2 t may have the heightcorresponding to the second portion 385-2 of the main spacer 385 and mayinclude the same material.

The component spacer positioned in the first element area DA2 isdescribed in detail as follows.

The first component spacer 385-1 t is positioned on the outside of therectangular area including two red light emitting diodes (LED) R, twoblue light emitting diodes (LED) B, and four green light emitting diodes(LED) G. In the embodiment of FIG. 22 , the first component spacer 385-1t is positioned on the outside of one unit pixel PXU2 in four places onthe top, bottom, left, and right, respectively, and when there is theportion where four first component spacers 385-1 t are positioned, arhombus structure may be formed. The material and height of the firstcomponent spacer 385-1 t may be the same as that of the first portion385-1 described in FIGS. 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,and 17 . The first component spacer 385-1 t may be formed of a positivetype of organic material, and for example, a photosensitive polyimide(PSPI) may be used. The entire height of the first component spacer385-1 t may be about 1.5 μm, and depending on the embodiment, it may be1.1 μm or more and 2.0 μm or less.

In one unit pixel PXU2, a black pixel defining layer 380 is formedcorresponding to an area surrounding the unit pixel PXU2. The area wherethe black pixel defining layer 380 is positioned overlaps with the areaoccupied by a total of eight pixels and the area occupied by the firstcomponent spacer 385-1 t of the periphery on a plane. An opening OP2 isdefined in the black pixel defining layer 380. Referring to FIG. 23 ,the black pixel defining layer 380 may have a structure connected to theblack pixel defining layer 380 of the adjacent unit pixel PXU2 byincluding portions extending vertically and horizontally. Referring toFIG. 23 , the black pixel defining layer 380 is not formed in the areacorresponding to the light transmission area LTA in addition to theopening OP2.

In FIG. 22 , the outline of each light emitting diode (LED) R, G, and Bis the opening OP2 positioned in the first element area DA2 of the blackpixel defining layer 380, and corresponds to the area where the emissionlayer EML of the corresponding pixel is positioned. The size of theopening OP2 positioned in the first element area DA2 is related to thelifetime of the emission layer EML, and when the material of theemission layer EML is determined, the opening OP2 may be formed with asize set in consideration of the lifetime.

On the other hand, although the anode included in each light emittingdiode (LED) R, G, and B is not shown, it includes the area of theopening OP2 of the black pixel defining layer 380 positioned in thefirst element area DA2, and an area additionally extended to theperiphery and a portion that is extended and connected to the underlyingpixel circuit unit.

On the black pixel defining layer 380, in addition to the firstcomponent spacer 385-1 t, a second component spacer 385-2 t is formed.In the first element area DA2, the first component spacer 385-1 t andthe second component spacer 385-2 t are formed separately from eachother.

The second component spacer 385-2 t, as shown in FIG. 22 , is positionedwithin the rectangular area where the eight light emitting diodes (LED)R, G, and B are positioned, and is positioned between the eight lightemitting diodes (LED) R, G, and B. In addition, the second componentspacer 385-2 t is formed across the opening OP2 of the adjacent blackpixel defining layer 380. The boundary of the opening OP2 of the blackpixel defining layer 380 and the boundary of the second component spacer385-2 t do not coincide and are spaced apart from each other at aregular interval.

On the other hand, in the embodiment of FIG. 22 , there is also aportion where the second component spacer 385-2 t is not positionedbetween adjacent light emitting diodes (LED), and in this case, twoadjacent light emitting diodes (LEDs) have the same color (in theembodiment of FIG. 22 , green) may be displayed. The second componentspacer 385-2 t according to the embodiment of FIG. 22 may have anH-shape, and in addition to the H-shape, may have a structure protrudedfrom side to side. According to an embodiment, the second componentspacer 385-2 t may be formed only in an H-shape.

In addition, the edge of the unit pixel PXU2 positioned outermost amongthe opening OP2 of the black pixel defining layer 380 and the edge ofthe second component spacer 385-2 t adjacent thereto may have ahorizontal interval of g−1. In the embodiment of FIG. 22 , an intervalof 5 μm is formed for each of a total of four edges, so that the secondcomponent spacer 385-2 t may have a structure that is not protruded tothe outside of the unit pixel PXU2 and is positioned inside.

The material and height of the second component spacer 385-2 t may bethe same as those of the second portion 385-2 described in FIG. 7 , etc.The second component spacer 385-2 t may be formed of the same materialas the first component spacer 385-1 t, and may be etched togetherthrough the same mask. The second component spacer 385-2 t may be formedof a positive type of organic material, and for example, photosensitivepolyimide (PSPI) may be used. The height of the second component spacer385-2 t may be about 0.4 μm, and may be 0.1 μm or more and 0.5 μm orless.

According to an embodiment, the first component spacer 385-1 t and thesecond component spacer 385-2 t may have a structure in which they areconnected to each other.

Referring to FIG. 23 , the light transmission area LTA is positionedbetween the four adjacent unit pixels PXU2, and the black pixel defininglayer 380, the light emitting diode (LED), and the pixel circuit unitpositioned below it are not formed so that light may be transmitted.

Hereinafter, the cross-section structure of the pixel and the lighttransmission area LTA of the first element area DA2 is described withreference to FIG. 24 .

First, the cross-section structure of the pixel of the first elementarea DA2 is described.

The pixel positioned in the first element area DA2 may have variousembodiments, and may have the same circuit and cross-section structureas that of the pixel positioned in the first display area DA1. Oneexample is shown in FIG. 28 described later and is described in FIG. 28in detail, and FIG. 24 examines the relationship between the firstelement area DA2 and the light transmission area LTA focusing on eachlayer except for the specific connection relationship. The layeredrelationship of the first element area DA2 of FIG. 24 may be the same asthe layered relationship of the first display area DA1.

The substrate 110 may include a material that does not bend due to arigid characteristic such as glass or a flexible material that may bebent, such as plastic or polyimide. FIG. 24 shows a flexible substrate,and a structure in which polyimide and a barrier layer positionedthereon and formed of an inorganic insulating material are doubleformed.

A metal layer BML is positioned on the substrate 110 and may have atriple layer structure. That is, each pixel formed in the first displayarea and the first element area has a plurality of thin film transistorsincluded in the pixel circuit unit, at least one thin film transistor ofa plurality of thin film transistors has a top gate structure (a gateelectrode is position on a semiconductor layer of which a channel of thethin film transistor is positioned), and the metal layer BML overlappingthe semiconductor layer is formed under the semiconductor layer.However, the metal layer BML of the first display area may be formed ofone layer formed of a metal, but the metal layer BML of the firstelement area additionally further includes the semiconductor layer BML1and the inorganic insulating layer BML2 in addition to the layer BML3corresponding to the metal layer BML of the first display area. Here,the semiconductor layer BML1 may include amorphous silicon, and theinorganic insulating layer BML2 may include a silicon oxide (SiO). Inaddition, each of the semiconductor layer BML1 and the inorganicinsulating layer BML2 may be formed as thin as 130 Å.

The reason for additionally forming the semiconductor layer BML1 and theinorganic insulating layer BML2 is to block light reflection. That is,an optical element such as a camera may be positioned under the firstelement area DA2, and then a lens is positioned on the front of theoptical element such as a camera, so that in order to remove a problemof being photographed by the camera while light is reflected between thelens and the metal layer BML3, the semiconductor layer BML1 and theinorganic insulating layer BML2 are thinly additionally formed.

The metal layer BML3 of the first element area DA2 may be formed of thesame material as the metal layer BML of the first display area DA1, andmay include a metal or a metal alloy such as copper (Cu), molybdenum(Mo), aluminum (Al), titanium (Ti), etc. and may consist of a singlelayer or multiple layers. In the present embodiment, the metal layerBML3 of the first element area DA2 may include molybdenum (Mo).

The metal layer BML is positioned in an area overlapping the channel ofthe first semiconductor layer ACT1 and/or the second semiconductor layerACT2. The metal layer BML is also called a lower shielding layer or alight blocking layer.

On top of the metal layer BML, a buffer layer 111 covering the metallayer BML may be positioned, and the buffer layer serves to block thepenetration of impurity elements into the first semiconductor layer, andmay be an inorganic insulating layer such as a silicon oxide (SiOx) or asilicon nitride (SiNx), a silicon oxynitride (SiONx), and the like.

A first semiconductor layer ACT1 is positioned on the buffer layer 111.The first semiconductor layer ACT1 includes a channel area, and a firstarea and a second area positioned on both sides of the channel area.

The first gate insulating layer 141 may be positioned to cover the firstsemiconductor layer ACT1 or to overlap only the channel area of thefirst semiconductor layer ACT1. That is, the first gate insulating layer141 does not overlap the second semiconductor layer ACT2. The first gateinsulating layer 141 may be an inorganic insulating layer including asilicon oxide (SiOx), a silicon nitride (SiNx), a silicon oxynitride(SiONx), or the like.

A first gate conductive layer GAT1 is positioned on the first gateinsulating layer 141, and the first gate conductive layer GAT1 includesa gate electrode of a transistor (LTPS TFT) including a siliconsemiconductor. The first gate conductive layer GAT1 may include a metalsuch as copper (Cu), molybdenum (Mo), aluminum (Al), titanium (Ti), or ametal alloy, and may be configured as a single layer or multiple layers.An area overlapping the gate electrode on a plane among the firstsemiconductor layer ACT1 may be a channel area.

The first gate conductive layer GAT1 is covered by a second gateinsulating layer 142, and the second gate insulating layer 142 may be aninorganic insulating layer including a silicon oxide (SiOx), a siliconnitride (SiNx), a silicon oxynitride (SiONx), or the like.

The second gate conductive layer GAT2 is positioned on the second gateinsulating layer 142, and the second gate conductive layer GAT2 includesa first storage electrode configuring the storage capacitor with thegate electrode and the lower shielding layer for the oxide semiconductortransistor positioned under the oxide semiconductor layer ACT2. Thesecond gate conductive layer GAT2 may include a metal or a metal alloysuch as copper (Cu), molybdenum (Mo), aluminum (Al), or titanium (Ti),and may be configured of a single layer or multiple layers.

The second gate conductive layer GAT2 is covered by a first interlayerinsulating layer 161, and the first interlayer insulating layer 161 mayinclude an inorganic insulating layer including a silicon oxide (SiOx),a silicon nitride (SiNx), a silicon oxynitride (SiONx), etc.

An oxide semiconductor layer ACT2 is positioned on the first interlayerinsulating layer 161, and the oxide semiconductor layer ACT2 includes achannel area, and a first area and a second area positioned on bothsides of the channel area.

The oxide semiconductor layer ACT2 is covered by a third gate insulatinglayer 143, and the third gate insulating layer 143 may include aninorganic insulating layer including a silicon oxide (SiOx), a siliconnitride (SiNx), a silicon oxynitride (SiONx), etc.

A third gate conductive layer GAT3 is positioned on the third gateinsulating layer 143. The third gate conductive layer GAT3 may include ametal or a metal alloy such as copper (Cu), molybdenum (Mo), aluminum(Al), or titanium (Ti), and may be composed of a single layer ormultiple layers.

The third gate conductive layer GAT3 is covered by a second interlayerinsulating layer 162, and the second interlayer insulating layer 162 mayinclude an inorganic insulating layer including a silicon oxide (SiOx),a silicon nitride (SiNx), a silicon oxynitride (SiONx), etc., andaccording to an embodiment, it may include an organic material.

A first data conductive layer SD1 is positioned on the second interlayerinsulating layer 162, and the first data conductive layer SD1 includes aconnecting part, thereby having a function for providing a voltage or acurrent to the first semiconductor layer ACT1 and the oxidesemiconductor layer ACT2 or for transmitting a voltage or a current toother elements. The first data conductive layer SD1 may include a metalsuch as aluminum (Al), copper (Cu), molybdenum (Mo), titanium (Ti), or ametal alloy, and may be configured as a single layer or multiple layers.

The first data conductive layer SD1 is covered by a first organic layer181. The first organic layer 181 may be an organic insulator includingan organic material, and the organic material may include at least onematerial selected from the group consisting of polyimide, polyamide,acryl resin, benzocyclobutene, and phenol resin.

A second data conductive layer SD2 is positioned on the first organiclayer 181. The second data conductive layer SD2 may be connected to thefirst data conductive layer SD1 through an opening penetrating the firstorganic layer 181. The second data conductive layer SD2 may include ametal or a metal alloy such as aluminum (Al), copper (Cu), molybdenum(Mo), or titanium (Ti), and may be configured as a single layer ormultiple layers.

The second data conductive layer SD2 is covered by a second organiclayer 182. The second organic layer 182 may be an organic insulator, andmay include at least one material selected from the group consisting ofpolyimide, polyamide, acryl resin, benzocyclobutene, and phenol resin.

A third organic layer 183 may be positioned on the second organic layer182, and may include at least one material selected from the groupconsisting of polyimide, polyamide, acryl resin, benzocyclobutene, andphenol resin. According to an embodiment, the third organic layer 183may not be included.

The organic layer 180 shown in FIG. 7 etc. may be one of the firstorganic layer 181, the second organic layer 182, and the third organiclayer 183, and in the embodiment of FIG. 21 , the organic layer 180 maycorrespond to the third organic layer 183.

The anode (Anode) is positioned on the third organic layer 183. Theanode (Anode) is connected to the second data conductive layer SD2 andthe first data conductive layer SD1 through the opening positioned inthe third organic layer 183 and/or the second organic layer 182 toreceive the output current from the transistor of the pixel circuitunit. The anode (Anode) may be composed of a single layer including atransparent conductive oxide film and a metal material, or a multi-layerincluding these. The transparent conductive oxide layer may includeIndium Tin Oxide (ITO), poly-ITO, Indium Zinc Oxide (IZO), IndiumGallium Zinc Oxide (IGZO) and Indium Tin Zinc Oxide (ITZO), and themetal material may include silver (Ag), molybdenum (Mo), copper (Cu),gold (Au), and aluminum (Al).

On top of the anode, a black pixel defining layer 380 having an openingoverlapping with at least part of the anode and covering the portion ofthe rest of the anode (Anode) is positioned. The black pixel defininglayer 380 may further include a light blocking material in addition tothe organic insulating material. The light blocking material includescarbon black, carbon nanotubes, a resin or paste including a black dye,metal particles such as nickel, aluminum, molybdenum, and alloysthereof, metal oxide particles (e.g., chromium nitride), etc. The blackpixel defining layer 380 may be formed of an organic material having anegative type of black color. Since the negative type of organicmaterial is used, it may have a characteristic that the portion coveredby the mask is removed.

An opening is defined in the black pixel defining layer 380, and theemission layer EML is positioned within the opening. The emission layerEML may be formed of an organic light emitting material, and theadjacent emission layer EMLs may display different colors. On the otherhand, according to an embodiment, each emission layer EML may displaylight of the same color due to the overlying color filter 230.

A spacer 385 is formed on the black pixel defining layer 380, but FIG.21 shows only the second spacer 385-2. However, on the black pixeldefining layer 380, as shown in FIG. 20 , in addition to the secondspacer 385-2, a first spacer 385-1 separated from the second spacer385-2 is also formed.

A functional layer FL is positioned on the spacer 385 and the exposedblack pixel defining layer 380, and the functional layer FL may beformed on the entire surface of the display panel DP. The functionallayer FL may include an electron injection layer, an electron transportlayer, a hole transport layer, and a hole injection layer, and may bedisposed on and under the emission layer EML. That is, as the holeinjection layer, the hole transport layer, the emission layer EML, theelectron transport layer, the electron injection layer, and the cathode(Cathode) are sequentially positioned on the anode (Anode), among thefunctional layer FL, the hole injection layer and the hole transportlayer may be disposed under the emission layer EML, and the electrontransport layer and the electron injection layer may be disposed on theemission layer EML.

The cathode may be formed as a light-transmitting electrode or areflecting electrode. According to an embodiment, the cathode may be atransparent or semi-transparent electrode, and may be formed of a metalthin film having a small work function, including lithium (Li), calcium(Ca), lithium fluoride/calcium (LiF/Ca), lithium fluoride/aluminum(LiF/Al), aluminum (Al), silver (Ag), magnesium (Mg), and a compoundthereof. In addition, a transparent conductive oxide (TCO) such asIndium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide (ZnO) orindium oxide (In2O3) may be further disposed on the metal thin film. Thecathode may be integrally formed over the entire surface of the displaypanel DP except for the light transmission area LTA.

An encapsulation layer 400 is positioned on the cathode (Cathode). Theencapsulation layer 400 includes at least one inorganic layer and atleast one organic layer, and in FIG. 24 , it has a triple layerstructure including the first inorganic encapsulation layer 401, theorganic encapsulation layer 402, and the second inorganic encapsulationlayer 403. The encapsulation layer 400 may be to protect the emissionlayer EML formed of an organic material from moisture or oxygen that maybe inflowed from the outside. According to an embodiment, theencapsulation layer 400 may include a structure in which an inorganiclayer and an organic layer are sequentially further stacked.

A detecting insulating layer 510 and a detecting electrode 540 arepositioned on the encapsulation layer 400 for touch sensing. In FIG. 24, only one detecting electrode 540 is shown, however as shown in FIG. 1, two detecting electrodes may be included. Here, the detectingelectrode 540 may include a metal or a metal alloy such as aluminum(Al), copper (Cu), silver (Ag), gold (Au), molybdenum (Mo), titanium(Ti), or tantalum (Ta), and may be composed of a single layer ormultiple layers.

A light blocking layer 220 and a color filter 230 are positioned on theoverlying detecting electrode 540.

The light blocking layer 220 may be positioned so as to overlap thedetecting electrode 540 in a plane view and may be positioned so as tonot overlap the anode (Anode) in a plane view. This is to prevent theanode (Anode) and the emission layer EML capable of displaying the imagefrom being obscured by the light blocking layer 220 and the detectingelectrode 540.

The color filter 230 is positioned on the detecting insulating layer 510and the light blocking layer 220. The color filter 230 includes a redcolor filter that transmits red light, a green color filter thattransmits green light, and a blue color filter that transmits bluelight. Each color filter 230 may be positioned so as to overlap with theanode (Anode) of a light emitting diode (LED) on a plane. Since lightemitted from the emission layer EML may be emitted while being changedinto a corresponding color while passing through the color filter, allof the light emitted from the emission layer EML may have the samecolor. However, in the emission layer EML, different colors of light aredisplayed, and the displayed color sense may be enhanced by passingthrough the color filter of the same color.

The light blocking layer 220 may be respectively positioned between thecolor filters 230. That is, the two color filters 230 are spaced apartfrom each other along the first direction DR1. According to anembodiment, the color filter 230 may be replaced with a color conversionlayer or may further include a color conversion layer. The colorconversion layer may include quantum dots.

A planarization layer 550 covering the color filter 230 and the lightblocking layer 220 is positioned on the color filter 230. Theplanarization layer 550 is for planarizing the upper surface of thelight emitting display panel, and may be a transparent organic insulatorincluding at least one material selected from the group consisting ofpolyimide, polyamide, acryl resin, benzocyclobutene, and phenol resin.

According to an embodiment, a low refractive layer and an additionalplanarization layer may be further positioned on the planarization layer550 to improve the front visibility and light output efficiency of thedisplay panel. Light may be emitted while being refracted to the frontby the low refractive layer and the additional planarization layerhaving a high refractive characteristic.

In the present embodiment, the polarizer is not included on theplanarization layer 550. That is, the polarizer may serve to prevent thedisplay deterioration while the user recognizes the external light as itis incident and reflected from the anode and the like. However, in thepresent embodiment, the black pixel defining layer 380 covers the sideof the anode (Anode) to reduce the degree of the reflection from theanode (Anode), and the light blocking layer 220 is also formed to reducethe incidence of light, thereby the structure to prevent thedeterioration of the display quality due to the reflection is alreadyincluded. Therefore, there is no need to separately from the polarizeron the front of the display panel DP.

In the above, the stacking relationship of the pixels in the firstelement area DA2 was described. Hereinafter, the stacking relationshipof the light transmission area LTA among the first element area DA2 isdescribed.

The light transmission area LTA removes the semiconductor, the metal,the light blocking layer 220, the color filter 230, and the black pixeldefining layer 380 so that light may be transmitted without blocking,and is laminated with only a transparent material. Transparent materialsinclude an inorganic insulating layer or an organic insulating layer,and may additionally include a functional layer FL. The structure inwhich the inorganic insulating layer or the organic insulating layer isstacked on the light transmission area LTA may be varied, and thestacked structure of the light transmission area LTA according to theembodiment of FIG. 24 is as follows.

A buffer layer 111 is positioned on the flexible substrate 110 includingpolyimide and a barrier layer, and a first organic layer 181 is formedon the buffer layer 111. The functional layer FL is positioned on thefirst organic layer 181, and the encapsulation layer 400 is positioneddirectly thereon. The upper layered structure of the encapsulation layer400 may be the same as the layer stacked on the pixel of the firstelement area DA2 except for the detecting electrode 540, the lightblocking layer 220, and the color filter 230. That is, the detectinginsulating layer 510 and the planarization layer 550 may be positionedon the encapsulation layer 400 in the light transmission area LTA.According to an embodiment, on the planarization layer 550 of the lighttransmission area LTA, a low refractive layer and an additionalplanarization layer may be further positioned to improve the frontvisibility and light output efficiency of the display panel.

In the pixel of the first element area DA2, the layer (the first gateinsulating layer 141, the second gate insulating layer 142, the firstinterlayer insulating layer 161, the third gate insulating layer 143,and the second interlayer insulating layer 162) stacked under the firstorganic layer 181 has been removed. However, according to an embodiment,at least one of these insulating layers may not be removed.

In addition, the second organic layer 182 and the third organic layer183 positioned on the first organic layer 181 in the pixel of the firstelement area DA2 are removed. However, according to an embodiment, atleast one of these organic layers may not be removed.

In addition, the cathode (Cathode) positioned on the functional layer FLis also removed, and additionally, the light blocking layer 220, thecolor filter 230, and the black pixel defining layer 380 are alsoremoved.

In the above, the structure of the unit pixel PXU2, the spacer 385, andthe light transmission area LTA in the first element area DA2 wasdescribed.

Hereinafter, the structure of the spacer 385 on the boundary portion ofthe first display area DA1 and the first element area DA2 is describedwith reference to FIG. 25 and FIG. 26 .

FIG. 25 is a top plan view schematically showing a first display areaand a first element area in a light emitting display panel according toan embodiment, and FIG. 26 is an enlarged view of a first display areaand a first element area according to an embodiment.

FIG. 25 shows the structure of openings OP and OP2 of the black pixeldefining layer 380 and the spacer 385 in the first display area DA1 andthe first element area DA2.

As shown in FIG. 25 , the openings OP and OP2 of the black pixeldefining layer 380 have different sizes in the first display area DA1and the first element area DA2, and the size of the opening OP2 formedin the first element area DA2 is larger than the size of the opening OPformed in the first display area DA1. This is to make up for thereduction in the number of pixels due to the light transmission area LTAby largely forming the light emitting diode (LED). In the opening OP ofthe first display area DA1 and in the opening OP2 of the first elementarea DA2, each of red, green, and blue emission layers are respectivelypositioned, and in FIG. 25 , the colors are distinguished throughhatching. However, the arrangement of the colors may vary according toan embodiment.

In FIG. 25 , the first portion 385-1 of the first display area DA1 isshown as a circle, and the second portion 385-2 of the first displayarea DA1 is positioned on the periphery thereof. The second portion385-2 may be positioned at a predetermined distance from the opening OPof the first display area DA1, and as shown in FIG. 9 , it may be formedentirely except for the opening OP and a portion exposing some blackpixel defining layer 380 in the first display area DA1.

On the other hand, in FIG. 25 , the first component spacer 385-1 t ofthe first element area DA2 is shown by a relatively large triangle, andin FIG. 25 , the second component spacer 385-2 t of the first elementarea DA2 is not shown. However, the second component spacer 385-2 t ofthe first element area DA2 may be formed in the same shape and positionas that of FIG. 22 .

The black pixel defining layer 380 is formed as a whole except for thelight transmission area LTA and the openings OP and OP2 so that theblack pixel defining layer 380 is positioned over the first display areaDA1, the first element area DA2, and the boundary area PDA positionedbetween the first display area DA1 and the first element area DA2.According to an embodiment, the black pixel defining layer 380 is formedin an island-shaped structure in the first element area DA2 and may bepositioned apart from the adjacent black pixel defining layer 380.

The opening OP and OP2 is not formed in the black pixel defining layer380 positioned in the boundary area PDA positioned between the firstdisplay area DA1 and the first element area DA2, and the portion wherethe black pixel defining layer 380 is not formed in the first elementarea DA2 may be the light transmission area LTA. Among the boundary areaPDA between the first display area DA1 and the first element area DA2, aboundary portion spacer 385 p is formed on the black pixel defininglayer 380. In the boundary portion spacer 385 p according to theembodiment of FIG. 25 , only the second boundary portion spacer 385-2 phaving the lower height is formed. In FIG. 25 , the second boundaryportion spacer 385-2 p is positioned in the boundary area PDA as a wholeand is connected to the second portion 385-2 of the first display areaDA1, and the end of the second boundary portion spacer 385-2 p may havea tapered structure at the boundary with the light transmission area LTAof the first element area DA2. That is, the boundary portion spacer 385p has a constant height and includes a second boundary portion spacer385-2 p having a tapered structure toward the first element area DA2.

In addition, the material and height of the boundary portion spacer 385p may be the same as that of the second portion 385-2 shown in FIG. 7and the like. The boundary portion spacer 385 p may be formed of apositive type of organic material, and as one example, thephotosensitive polyimide (PSPI) may be used. The height of the secondboundary portion spacer 385-2 p may be about 0.4 μm, and may be 0.1 μmor more and 0.5 μm or less. However, according to an embodiment, theboundary portion spacer 385 p may be formed to be larger or smaller thanthe spacer 385 of the first display area DA1.

In FIG. 26 , unlike FIG. 25 , the structure in which the boundaryportion spacer 385 p also includes the first boundary portion spacer385-1 p having the higher height than the second boundary portion spacer385-2 p is shown. The first portion 385-1 and the first boundary portionspacer 385-1 p of the first display area DA1 are shown as a circle.

The boundary portion spacer 385 p according to the embodiment of FIG. 26includes a first boundary portion spacer 385-1 p and a second boundaryportion spacer 385-2 p.

The second boundary portion spacer 385-2 p is positioned in the boundaryarea PDA as a whole and is connected to the second portion 385-2 of thefirst display area DA1, and at the boundary with the first element areaDA2, the end of the second boundary portion spacer 385-2 p may have thetapered structure.

The first boundary portion spacer 385-1 p of the boundary portion spacer385 p, as shown in FIG. 26 , may be positioned sparsely and have thehigher height than the second boundary portion spacer 385-2 p. In thepresent embodiment, the boundary portion spacer 385 p may have the samesize and shape as the spacer 385 of the first display area DA1. As aresult, the cross-section structure of the boundary portion spacer 385 pmay be referred to as a spacer 385 shown in FIG. 2 . That is, theboundary portion spacer 385 p has a constant height and may include afirst boundary portion spacer 385-1 p having the higher height than thesecond boundary portion spacer 385-2 p along with the second boundaryportion spacer 385-2 p having the taper structure toward the firstelement area DA2.

In addition, the material and height of the boundary portion spacer 385p maybe the same as the spacer 385 described in FIGS. 7, 8, 9, 10, 11,12, 13, 14, 15, 16 , and 17. The boundary portion spacer 385 p may beformed of a positive type of organic material, and for example, thephotosensitive polyimide (PSPI) may be used. The entire height of thefirst boundary portion spacer 385-1 p may be about 1.5 μm, and may be1.1 μm or more and 2.0 μm or less. In addition, the second boundaryportion spacer 385-2 p may have a height of about 0.4 μm, and may be 0.1μm or more and 0.5 μm or less. However, according to an embodiment, theboundary portion spacer 385 p may be formed larger or smaller than thespacer 385 of the first display area DA1. Meanwhile, according to anembodiment, the first boundary portion spacer 385-1 p may have the lowerheight than the first portion 385-1 of the first display area DA1.

Hereinafter, the scratch strength of the first element area DA2 isdescribed with reference to FIG. 27 .

FIG. 27 is a view showing a comparison of scratch strength of a firstelement area according to an embodiment and a comparative example.

In FIG. 27 , as a comparative example, a first comparative example Ref.1and a second comparative example Ref.2 are described and have the samecharacteristic as two comparative examples Ref. 1 and Ref. 2 describedin FIG. 16 . However, in FIG. 27 , the scratch strength is compared byusing two comparative examples for each of comparative examples Ref.1and Ref.2. In FIG. 27 , for the structure of the present embodiment, twoembodiments (Embodiment 1, Embodiment 2) are also included.

In FIG. 27 , two embodiments (Embodiment 1, Embodiment 2) areembodiments generated through the same process conditions as each other.Also, two comparative examples included in the comparative examplesRef.1 and Ref.2 are formed through the same process conditions.

The scratch strength test of FIG. 27 was conducted while sequentiallyapplying a pressure using an instrument with a ball tip diameter of 2mm.

In FIG. 27 , the position where the unit pixel is defective with respectto the scratch strength in the first element area DA2 is shown with acheck mark, and a crack load value at the position where the defectoccurs is also described.

By comparison, it may be confirmed that the second comparative exampleRef.2 has the highest scratch strength. However, since the secondcomparative example Ref.2 does not use the black pixel defining layer380, there is a drawback that a separate polarizer must be attached toreflect the external light. In addition, in terms of the scratchstrength, it may be confirmed that the embodiment does not significantlydecrease compared to the second comparative example Ref.2.

Meanwhile, comparing the first comparative example Ref. 1 using theblack pixel defining layer 380 with the embodiment, it may be confirmedthat there is a significant difference in the scratch strength. As aresult, like the present embodiment, in forming the second portion 385-2overlapping with the wide area on the black pixel defining layer 380compared to the first comparative example Ref.1 forming the high firstportion only in the narrow area, the scratch strength is high enough,and it has a merit that an inferiority rate is reduced.

Hereinafter, the circuit structure of the pixel is described withreference to FIG. 28 .

First, the circuit structure of one pixel is described through FIG. 28 .

FIG. 28 is a circuit diagram of one pixel included in light emittingdisplay panel according to an embodiment.

The circuit structure shown at FIG. 28 is a circuit structure of a pixelcircuit unit and a light emitting diode (LED) formed in the firstdisplay area DA1 and the first element area DA2.

One pixel according to an embodiment includes a plurality of transistorsT1, T2, T3, T4, T5, T6, and T7, a storage capacitor Cst, a boostcapacitor C_(boost) and a light emitting diode (LED) that are connectedto several wires 127, 128, 151, 152, 153, 155, 171, 172, and 741. Here,the transistors and capacitor excluding the light emitting diodes LEDconstitute a pixel circuit unit. According to an embodiment, the boostcapacitor C_(boost) may be omitted.

A plurality of wires 127, 128, 151, 152, 153, 155, 171, 172, and 741 areconnected to one pixel PX. A plurality of wires include a firstinitialization voltage line 127, a second initialization voltage line128, a first scan line 151, a second scan line 152, an initializationcontrol line 153, a light emitting control line 155, a data line 171, adriving voltage line 172, and a common voltage line 741. In theembodiment of FIG. 28 , the first scan line 151 connected to the seventhtransistor T7 is also connected to the second transistor T2, accordingto an embodiment, and the seventh transistor T7 may be connected with aseparate bypass control line differently from the second transistor T2.

The first scan line 151 is connected to a scan driver (not shown) totransmit a first scan signal GW to the second transistor T2 and theseventh transistor T7. A voltage of an opposite polarity to a voltageapplied to the first scan line 151 may be applied to the second scanline 152 with the same timing as the signal of the first scan line 151.For example, when a negative voltage is applied to the first scan line151, a positive voltage may be applied to the second scan line 152. Thesecond scan line 152 transmits a second scan signal GC to the thirdtransistor T3. The initialization control line 153 transmits aninitialization control signal GI to the fourth transistor T4. The lightemission control line 155 transmits a light emission control signal EMto the fifth transistor T5 and the sixth transistor T6.

The data line 171 is a wire transmitting a data voltage DATA generatedfrom a data driver (not shown), and accordingly a luminance emitted bythe light emitting diode (LED) is changed as a magnitude of the lightemitting current transmitted to the light emitting diode LED is changed.The driving voltage line 172 applies a driving voltage ELVDD. The firstinitialization voltage line 127 transmits a first initialization voltageVinit, and the second initialization voltage line 128 transmits a secondinitialization voltage AVinit. The common voltage line 741 applies acommon voltage ELVSS to the cathode of the light emitting diode LED. Inthe present exemplary embodiment, the voltages applied to the drivingvoltage line 172, the first and second initialization voltage lines 127and 128, and the common voltage line 741 may be a constant voltage,respectively.

The driving transistor T1 (also referred to as a first transistor) is ap-type transistor and has a silicon semiconductor as a semiconductorlayer. It is a transistor that adjusts the magnitude of the lightemitting current output to the anode of the light emitting diode LEDaccording to the magnitude of the voltage (i.e., a voltage stored in thestorage capacitor Cst) of the gate electrode of the driving transistorT1. Since the brightness of the light emitting diode LED is adjustedaccording to the magnitude of the light emitting current output to theanode of the light emitting diode LED, the light emitting luminance ofthe light emitting diode LED may be adjusted according to the datavoltage DATA applied to the pixel. For this purpose, the first electrodeof the driving transistor T1 is disposed to receive the driving voltageELVDD and is connected to the driving voltage line 172 via the fifthtransistor T5. Also, the first electrode of the driving transistor T1 isconnected to the second electrode of the second transistor T2 to receivethe data voltage DATA. On the other hand, the second electrode of thedriving transistor T1 outputs the light emitting current to the lightemitting diode LED and is connected to the anode of the light emittingdiode LED via the sixth transistor T6 (hereinafter, referred to as anoutput control transistor). In addition, the second electrode of thedriving transistor T1 is also connected to the third transistor T3 totransmit the data voltage DATA applied to the first electrode to thethird transistor T3. Meanwhile, the gate electrode of the drivingtransistor T1 is connected to one electrode (hereinafter, referred to asa second storage electrode) of the storage capacitor Cst. Accordingly,the voltage of the gate electrode of the driving transistor T1 changesaccording to the voltage stored in the storage capacitor Cst, andaccordingly, the light emitting current output by the driving transistorT1 is changed. The storage capacitor Cst serves to keep the voltage ofthe gate electrode of the driving transistor T1 constant for one frame.Meanwhile, the gate electrode of the driving transistor T1 may also beconnected to the third transistor T3 so that data voltage DATA appliedto the first electrode of the driving transistor T1 may be transmittedto the gate electrode of the driving transistor T1 through the thirdtransistor T3. The gate electrode of the driving transistor T1 is alsoconnected to the fourth transistor T4 and may be initialized byreceiving the first initialization voltage Vinit.

The second transistor T2 is a p-type transistor and has a siliconsemiconductor as a semiconductor layer. The second transistor T2 is atransistor that receives the data voltage DATA into the pixel. The gateelectrode of the second transistor T2 is connected to the first scanline 151 and one electrode (hereinafter, referred to as ‘a lower boostelectrode’) of the boost capacitor C_(boost). The first electrode of thesecond transistor T2 is connected to the data line 171. The secondelectrode of the second transistor T2 is connected to the firstelectrode of the driving transistor T1. When the second transistor T2 isturned on by the negative voltage of the first scan signal GWtransmitted through the first scan line 151, the data voltage DATAtransmitted through the data line 171 is transmitted to the firstelectrode of the driving transistor T1 and the data voltage DATA isfinally transmitted to the gate electrode of the driving transistor T1and stored in the storage capacitor Cst.

The third transistor T3 is an n-type transistor and has an oxidesemiconductor as a semiconductor layer. The third transistor T3 iselectrically connected to the second electrode of the driving transistorT1 and the gate electrode of the driving transistor T1. As a result, itis a transistor that allows the data voltage DATA to be compensated bythe threshold voltage of the driving transistor T1 and then stored inthe second storage electrode of the storage capacitor Cst. The gateelectrode of the third transistor T3 is connected to the second scanline 152, and the first electrode of the third transistor T3 isconnected to the second electrode of the driving transistor T1. Thesecond electrode of the third transistor T3 is connected to the secondstorage electrode of the storage capacitor Cst, the gate electrode ofthe driving transistor T1, and the other electrode of the boostcapacitor C_(boost) (hereinafter, referred to as ‘an upper boostelectrode’). The third transistor T3 is turned on by the positivevoltage among the second scan signal GC transmitted through the secondscan line 152 to connect the gate electrode of the driving transistor T1and the second electrode of the driving transistor T1 and to transmitthe voltage applied to the gate electrode of the driving transistor T1to the second storage electrode of the storage capacitor Cst to bestored to the storage capacitor Cst. At this time, the voltage stored inthe storage capacitor Cst is stored in a state in which the voltage ofthe gate electrode of the driving transistor T1 when the drivingtransistor T1 is turned off is stored, and then the voltage of thethreshold voltage Vth of the driving transistor T1 is compensated.

The fourth transistor T4 is an n-type transistor and has an oxidesemiconductor as a semiconductor layer. The fourth transistor T4initializes the gate electrode of the driving transistor T1 and thesecond storage electrode of the storage capacitor Cst. The gateelectrode of the fourth transistor T4 is connected to the initializationcontrol line 153, and the first electrode of the fourth transistor T4 isconnected to the first initialization voltage line 127. The secondelectrode of the fourth transistor T4 is connected to the secondelectrode of the third transistor T3, the second storage electrode ofthe storage capacitor Cst, the gate electrode of the driving transistorT1, and the upper boost electrode of the boost capacitor C_(boost). Thefourth transistor T4 is turned on by the positive voltage of theinitialization control signal GI received through the initializationcontrol line 153, and at this time, the first initialization voltageVinit is transmitted to the gate electrode of the driving transistor T1,the second storage electrode of the storage capacitor Cst, and the upperboost electrode of the boost capacitor C_(boost) to be initialized.

The fifth transistor T5 and the sixth transistor T6 are p-typetransistors, and have a silicon semiconductor as a semiconductor layer.

The fifth transistor T5 serves to transfer the driving voltage ELVDD tothe driving transistor T1. The gate electrode of the fifth transistor T5is connected to the light emitting control line 155, the first electrodeof the fifth transistor T5 is connected to the driving voltage line 172,and the second electrode of the fifth transistor T5 is connected to thefirst electrode of the driving transistor T1.

The sixth transistor T6 serves to transfer the light emitting currentoutput from the driving transistor T1 to the light emitting diode LED.The gate electrode of the sixth transistor T6 is connected to the lightemitting control line 155, the first electrode of the sixth transistorT6 is connected to the second electrode of the driving transistor T1,and the second electrode of the sixth transistor T6 is connected to theanode of the light emitting diode LED.

The seventh transistor T7 is a p-type or n-type transistor, and thesemiconductor layer has a silicon semiconductor or oxide semiconductor.The seventh transistor T7 serves for initializing the anode of the lightemitting diode LED. The gate electrode of the seventh transistor T7 isconnected to the first scan line 151, the first electrode of the seventhtransistor T7 is connected to the anode of light emitting diode LED, andthe second electrode of the seventh transistor T7 is connected to thesecond initialization voltage line 128. When the seventh transistor T7is turned on by the negative voltage of the first scan line 151, thesecond initialization voltage AVinit is applied to the anode of thelight emitting diode LED to be initialized. On the other hand, the gateelectrode of the seventh transistor T7 may be connected to a separatebypass control line and may be controlled by the first scan line 151 andseparate wiring. In addition, according to an embodiment, the secondinitialization voltage line 128 to which the second initializationvoltage AVinit is applied may be the same as the first initializationvoltage line 127 to which the first initialization voltage Vinit isapplied.

It is described that one pixel PX includes the seven transistors T1 toT7, two capacitors (the storage capacitor Cst, the boost capacitorC_(boost)), however it is not limited thereto, and according to anembodiment, the boost capacitor C_(boost) may be omitted. Also, even inan embodiment in which the third transistor and the fourth transistorare formed of an n-type transistor, only one of them may be formed as ann-type transistor or the other transistor may be formed as an n-typetransistor.

In the above, the circuit structure of the pixel formed in the displayarea DA was described with reference to FIG. 28 .

A reflection adjusting layer may be disposed on the light blockinglayer. The reflection adjusting layer may selectively absorb light of awavelength of a partial band among light reflected inside the displaydevice or light incident outside the display device. The reflectionadjusting layer may fill the opening OP.

For example, the reflection adjusting layer absorbs a first wavelengthregion of 490 nm to 505 nm and a second wavelength region of 585 nm to600 nm, and thus light transmittance in the first wavelength region andsecond wavelength region may be 40% or less. The reflection adjustinglayer may absorb light of a wavelength outside the emission wavelengthrange of red, green, or blue emitted from the light emitting diode ED.As described, the reflection adjusting layer absorbs light of awavelength that does not belong to a wavelength range of red, green, orblue emitted from the light emitting diode, thereby preventing orminimizing the reduction in luminance of the display device andsimultaneously preventing or minimizing the deterioration of theluminous efficiency and improving visibility of the display device.

In the embodiment, the reflection adjusting layer may be provided as anorganic material layer including a dye, a pigment, or combinationthereof. The reflection adjusting layer may contain a tetraazaporphyrin(TAP)-based compound, a porphyrin-based compound, a metalporphyrin-based compound, an oxazine-based compound, and asquarylium-based compound, a triarylmethane compound, a polymethinecompound, an anthraquinone compound, a phthalocyanine compound, an azocompound, a perylene compound, a xanthene-based compound, adiammonium-based compound, a dipyrromethene-based compound, acyanine-based compound, and a combination thereof.

In the embodiment, the reflection adjusting layer may have transmittanceof about 64% to 72%. The transmittance of the reflection adjusting layermay be adjusted according to the content of the pigment and/or dyeincluded in the reflection adjusting layer.

According to embodiments, the reflection adjusting layer may not bedisposed in the component area DA2. In addition, an embodiment includingthe reflection adjusting layer may further include a capping layer and alow reflection layer disposed between the cathode (Cathode) and theencapsulation layer 400.

The capping layer may serve to improve the luminous efficiency of thelight emitting diode ED by the principle of constructive interference.The capping layer may include, for example, a material having arefractive index of 1.6 or more for light having a wavelength of 589 nm.

The capping layer may be an organic capping layer including an organicmaterial, an inorganic capping layer including an inorganic material, ora composite capping layer including an organic material and an inorganicmaterial. For example, the capping layer may contain a carbocycliccompound, a heterocyclic compound, an amine group-containing compound, aporphine derivative, a phthalocyanine derivative, a naphthalocyaninederivative, an alkali metal complex, alkaline earth metal complexes, orany combination thereof. The carbocyclic compounds, the heterocycliccompounds, and the amine group-containing compounds may be optionallysubstituted with substituents including O, N, S, Se, Si, F, Cl, Br, I,or any combination thereof.

A low reflection layer may be disposed on the capping layer. The lowreflective layer may overlap a front surface of the substrate 110.

The low reflective layer may include an inorganic material having lowreflectance, and in an embodiment, it may include a metal or metaloxide. When the low reflective layer contains a metal, it may include,for example, ytterbium (Yb), bismuth (Bi), cobalt (Co), molybdenum (Mo),titanium (Ti), zirconium (Zr), aluminum (Al), chromium (Cr), niobium(Nb), platinum (Pt), tungsten (W), indium (In), tin (Sn), iron (Fe),nickel (Ni), tantalum (Ta), manganese (Mn), and it may include zinc(Zn), germanium (Ge), silver (Ag), magnesium (Mg), gold (Au), copper(Cu), calcium (Ca), or a combination thereof. In addition, when the lowreflective layer contains a metal oxide, it may include, for example,SiO₂, TiO₂, ZrO₂, Ta₂O₅, HfO₂, Al₂O₃, ZnO, Y₂O₃, BeO, MgO, PbO₂, WO₃,SiN_(x), LiF, CaF₂, MgF₂, CdS, or a combination thereof.

In the embodiment, an absorption coefficient (k) of the inorganicmaterial included in the low reflective layer may be 4.0 or less and 0.5or more (0.5≤k≤4.0). In addition, the inorganic material included in thelow reflective layer may have a refractive index (n) of 1 or more(n≥1.0).

The low reflective layer induces destructive interference between thelight incident into the display device and the light reflected from themetal disposed under the low reflective layer, thereby reducingreflection of external light. Accordingly, the display quality andvisibility of the display device can be improved by reducing thereflection of the external light of the display device through the lowreflective layer.

According to embodiments, the capping layer may not be formed, and thenthe low reflective layer may be contact the cathode (Cathode) directly.

The encapsulation layer is disposed on the low reflective layer, otherstructures may be the same as FIGS. 7 and 24 .

While this disclosure has been described in connection with what ispresently considered to be practical embodiments, it is to be understoodthat the disclosure is not limited to the disclosed embodiments. On thecontrary, it is intended to cover various modifications and equivalentarrangements included within the spirit and scope of the appendedclaims.

What is claimed is:
 1. A light emitting display device comprising: asubstrate; an anode positioned on the substrate; a black pixel defininglayer, wherein an opening overlapping an anode is defined in the blackpixel defining layer; an emission layer positioned in the opening of theblack pixel defining layer; a spacer positioned on the black pixeldefining layer and having a step; and a cathode formed on the emissionlayer, the black pixel defining layer, and the spacer, wherein thespacer has a first portion and a second portion having a lower heightthan the first portion and integrally formed with the first portion, andone of end portions of the second portion is positioned closer to theopening than one of end portions of the first portion.
 2. The lightemitting display device of claim 1, wherein the second portion ispositioned away from the opening of the black pixel defining layer by apredetermined distance.
 3. The light emitting display device of claim 2,wherein a planar area ratio of the black pixel defining layer covered bythe spacer is 50% or more and 95% or less.
 4. The light emitting displaydevice of claim 1, wherein the spacer is formed of a photosensitivepolyimide (PSPI) or a positive type of photosensitive organic material,and the black pixel defining layer includes alight blocking material andis formed of an organic material having a negative type of black color.5. The light emitting display device of claim 1, wherein a height of thefirst portion is 1.1 μm or more and 2.0 μm or less, and a height of thesecond portion is 0.1 μm more and 0.5 μm or less.
 6. The light emittingdisplay device of claim 1, further comprising: an encapsulation layerpositioned on the cathode; a detecting insulating layer and a detectingelectrode positioned on the encapsulation layer; and alight blockinglayer and a color filter positioned on the detecting insulating layerand the detecting electrode.
 7. The light emitting display device ofclaim 1, further comprising afunctional layer disposed under the cathodeand positioned on the black pixel defining layer, the emission layer,and the spacer, the functional layer includes a hole injection layer,and the hole injection layer is in contact with the black pixel defininglayer and the spacer.
 8. A light emitting display device comprising amain display area and a component area, wherein the component areaincludes: a unit pixel including a plurality of light emitting diodes(LEDs); a component spacer positioned on the periphery of the pluralityof light emitting diodes (LEDs) included in the unit pixel; and alighttransmission area positioned on the periphery of the unit pixel, whereinthe component spacer includes a first component spacer positionedoutside the unit pixel, and a second component spacer positioned betweenthe plurality of light emitting diodes (LEDs) included in the unitpixel, and wherein the second component spacer has a lower height thanthe first component spacer, and the second component spacer and thefirst component spacer are spaced apart from each other.
 9. The lightemitting display device of claim 8, wherein the unit pixel furtherincludes a black pixel defining layer having a plurality of openings,and a plurality of openings of the black pixel defining layer correspondone-to-one to the plurality of light emitting diodes (LEDs) included inthe unit pixel.
 10. The light emitting display device of claim 9,wherein four of the first component spacers are formed outside the unitpixel, and when four first component spacers are connected, a rhombusstructure is formed on a plane.
 11. The light emitting display device ofclaim 10, wherein the second component spacer is positioned in arectangular area formed by the plurality of light emitting diodes (LEDs)and is formed crossing between a plurality of openings of the blackpixel defining layer.
 12. The light emitting display device of claim 11,wherein the second component spacer is spaced apart from a plurality ofopenings of the black pixel defining layer by a predetermined distanceon a plane.
 13. The light emitting display device of claim 12, whereinthe second component spacer is not positioned in a part between aplurality of openings adjacent to the black pixel defining layer. 14.The light emitting display device of claim 13, wherein the secondcomponent spacer has a protruded structure from right to left inaddition to an H-shape.
 15. The light emitting display device of claim12, wherein an edge positioned at the outermost side of the unit pixelamong a plurality of openings of the black pixel defining layer and anedge of the second component spacer adjacent to the edge have a distanceof about 5 μm from each other.
 16. The light emitting display device ofclaim 12, wherein a boundary portion spacer is formed on the boundaryarea positioned between the main display area and the component area,and the boundary portion spacer includes a second boundary portionspacer having a constant height and having a tapered structure at oneend on a boundary with the light transmission area.
 17. The lightemitting display device of claim 16, wherein the height of the secondboundary portion spacer is 0.1 μm or more and 0.5 μm or less.
 18. Thelight emitting display device of claim 16, wherein the spacer and theboundary portion spacer are formed of a photosensitive polyimide (PSPI)or a positive type of photosensitive organic material, and the blackpixel defining layer includes alight blocking material and is formed ofan organic material with a negative type of black color.
 19. The lightemitting display device of claim 17, wherein an opening of the blackpixel defining layer is positioned in the main display area, the mainspacer is positioned in the periphery of the opening in the main displayarea, the main spacer includes a first portion and a second portionhaving a lower height than the first portion and integrally formed withthe first portion, and the second portion is positioned close to theopening in the main display area.
 20. The light emitting display deviceof claim 19, wherein the planar area ratio of the black pixel defininglayer covered by the main spacer is 50% or more and 95% or less.